Back to current seminars
The ALS holds seminars regularly, both as part of our colloquium series and on an ad hoc basis. This page lists seminars we have hosted in the past. To receive notifications of all seminars, please email ALS-Admin@lbl.gov to request to be added to the distribution list.
Winter 2022 Colloquium Series
JANUARY 12Elspeth Garman, Oxford University10:00–11:00 am Pacific Estimating Doses for Synchrotron Experiments: Why and How Abstract In synchrotron macromolecular and small molecule crystallography, SAXS, and protein footprinting experiments, the effects of radiation damage to the sample during the measurement can adversely affect the integrity of the results. The fundamental metric against which indicators of radiation damage are plotted is the dose, the energy absorbed per unit mass of the sample. The dose can be estimated from knowledge of the beam characteristics (energy, flux, size, intensity profile) and the atomic contents of the sample (and solvent composition), which allows the amount of x-ray absorption to be calculated. Once the dose has been estimated, data collection conditions can be adjusted to ensure that the results will not be compromised by radiation damage. The program RADDOSE permitted the dose to be computed, but was not designed to take into account the rotation of the sample in the beam, since it was instigated when beams were usually larger than most crystals. The code reported the maximum dose absorbed, which was usually at the centre of the sample if a beam with a Gaussian profile was being used. This dose could be much larger than the average dose absorbed by the irradiated volume of the crystal. To address these issues, we have written software for temporally and spatially resolved modelling of absorbed dose [1], RADDOSE-3D [www.raddo.se] for particular data strategies. We also introduced and validated a new dose metric, Diffraction Weighted Dose, DWD [2], which combines information from the aggregation of dose within each volume element of the crystal up to a given time, with the way the crystal is being exposed at that moment. The resulting dose value is lower than the maximum dose experienced by localised volumes of the crystal, but DWD more realistically represents the damage state of the crystal during the experiment. However, it is still not ideal, a fact that will be discussed in this talk. Further developments to RADDOSE-3D have been implemented to make it appropriate for estimating doses absorbed in small molecule crystallography [3] and SAXS [4] experiments, as well as by micro and nano-crystals [7] now used at synchrotrons and XFELS [6]. The code takes into account the energy carried away by photoelectrons which escape from these small crystals as well as that entering from irradiated solvent around them. Very recently we have written a GUI to allow RADDOSE-3D to be used conveniently by experimenters at synchrotron beamlines. References: [1] O. B Zeldin, M. Gerstel & E.F. Garman (2013) Optimising the spatial distribution of dose in X-ray macromolecular crystallography. J. Synchrotron Radiation 20, 49–57 [2] O. B. Zeldin, S. Brockhauser, J. Bremridge, J. Holton & E.F. Garman (2013) Predicting the X-ray lifetime of protein crystals. PNAS 110, 20551-20556 [3] J. Christensen, P.N. Horton, C.S. Bury, J.L. Dickerson, H. Taberman, E.F. Garman*, & S.J. Coles* (2019) Radiation damage in small molecule crystallography: fact not fiction IUCrJ 6, 703–713 [4] J.C. Brooks-Bartlett, R.A. Batters, C.S. Bury, E.D. Lowe, H.M. Ginn, A. Round & E.F. Garman. (2017) Development of tools to automate quantitative analysis of radiation damage in SAXS experiments. J. Synchrotron Radiation 24, 63–72 [5] J.L. Dickerson &E.F. Garman. (2021) Doses for experiments with microbeams and microcrystals :Monte Carlo simulations in RADDOSE-3D. Protein Science. 30, 8–19 [6] J.L. Dickerson, P.T.N. McCubbin & E.F. Garman (2020) RADDOSE-XFEL : femtosecond time-resolved dose estimates for macromolecular X-ray free-electron laser experiments. J. Appl. Cryst. 53, 549–560 Biography Elspeth Garman started her working life aged 18 as a volunteer teacher in Swaziland, Southern Africa. Following a degree in Physics at Durham University, she did a D.Phil (PhD) in Experimental Nuclear Structure Physics at Oxford University. After seven years as a Nuclear Physics Research Officer and Physics Tutor, she changed fields to protein crystallography. Her main research interests are in improving methods for structural biology, including establishing cryocooling protocols and metrics for assessing radiation damage in x-ray crystallography as well as applying proton-induced x-ray emission (PIXE) techniques to unambiguously identify metals in proteins. She was President of the British Crystallographic Association from 2009–2012 and Director of the Life Sciences Interface and then Systems Biology EPSRC Doctoral Training Centres at Oxford from 2009–2014, was awarded the European Crystallographic Association’s Max Perutz Prize in 2019, and is Professor of Molecular Biophysics at Oxford University. |
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JANUARY 26Sarbajit Banerjee, Texas A&M3:00–4:00 pm Pacific Designing Electrode Architectures across Length Scales: Some Lessons Learned from Li-ion and “Beyond Li” Chemistries Abstract The design and operation of rechargeable batteries is predicated on orchestrating flows of mass, charge, and energy across multiple interfaces. Understanding such flows requires knowledge of atomistic and mesoscale diffusion pathways and the coupling of ion transport with electron conduction. Using multiple polymorphs of V2O5 as model systems, I will discuss our efforts to develop an Angstrom-level view of diffusion pathways using a combination of single-crystal X-ray diffraction and density functional theory calculations. Scanning transmission X-ray microscopy and ptychography imaging provides a means of mapping the accumulative results of atomic scale inhomogeneities at mesoscale dimensions and further enables tracing of stress gradients across individual particles. I will discuss mitigation of diffusion impediments with reference to two distinct approaches: (a) utilization of Riemann manifolds as a geometric design principle for electrode architectures and (b) the atomistic design of polymorphs with well-defined diffusion pathways that provide frustrated coordination. The latter approach, involving navigating metastable phase space, holds opportunities for non-equilibrium structural motifs and distinctive chemical bonding and ultimately for the realization of novel function. Using binary, ternary, and quaternary oxides of vanadium, as illustrative examples where topochemical synthetic strategies have unveiled novel polymorphs, I will highlight the tunability of electronic structure, the potential richness of energy landscapes, and the implications for discovering promising intercalation hosts for both multivalent and anion batteries. Biography Sarbajit Banerjee is the Davidson Chair Professor of Chemistry, Professor of Materials Science & Engineering, and Chancellor EDGES Fellow at Texas A&M University. He was awarded a National Science Foundation CAREER award in 2009; the American Chemical Society ExxonMobil Solid-State-Chemistry Fellowship in 2010; the Cottrell Scholar Award in 2011; the Minerals, Metals, and Materials Society Young Leader Award in 2013; the American Chemical Society Journal of Physical Chemistry Lectureship in 2013; the Scialog Innovation Fellowship in 2013; the IOM3 Rosenhain Medal and Prize in 2015; and the Royal Society of Chemistry/IOM3 Beilby Medal in 2016. In 2012, MIT Technology Review named Sarbajit to its global list of “Top 35 innovators under the age of 35” for the discovery of dynamically switchable smart window technologies that promise a dramatic reduction in the energy footprint of buildings. He was named a NASA NIAC Fellow in 2021 and has received two Special Creativity Awards from the National Science Foundation (2020 and 2021). He was awarded the 2018 Robert S. Hyer Graduate Student Mentor Award by the Texas Section of the American Physical Society and is the 2021 recipient of the Stanley C. Israel Regional Award for Advancing Diversity in the Chemical Sciences from the American Chemical Society. He serves as Senior Editor of ACS Omega and is a Fellow of the Royal Society of Chemistry and the Institute of Physics. |
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FEBRUARY 9Aaron Lindenberg, Stanford and SLAC National Accelerator Laboratory3:00–4:00 pm Pacific Ultrafast Probes of Nanoscale Heterogeneous Dynamics Abstract Whereas it is fairly straightforward using current ultrafast x-ray and electron scattering techniques to capture coherent atomic-scale dynamics at the unit cell level via crystallographic approaches, the dynamic disorder, heterogeneity, and fluctuations that occur during materials switching events remain largely mysterious. Here I will describe recent efforts to probe such dynamic atomic-scale responses using two examples: In the hybrid perovskites I will show how transient diffuse scattering approaches enable a new understanding of local nanoscale polaronic distortions and the fundamental processes that accompany absorption of a photon. I will also describe recent efforts using single-shot pump-probe x-ray photon correlation spectroscopy to visualize fundamental nucleation processes during the formation of a new light-induced metastable structure. Biography Aaron M. Lindenberg is an Associate Professor at Stanford University with joint appointments in the Department of Materials Science and Engineering and the Department of Photon Science. He received his B.A. from Columbia University in 1996 and his Ph.D. in Physics from the University of California, Berkeley in 2001. He was a Faculty Fellow at Berkeley from 2001-2003 and then a staff scientist at the SLAC National Accelerator Laboratory from 2003-2007. He is a winner of the DARPA Young Faculty Award, the Department of Energy Outstanding Mentor Award, the Alfred Moritz Michaelis Prize, and was named a Terman Fellow and a Chambers Faculty Scholar at Stanford and an I.I. Rabi Scholar at Columbia. |
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FEBRUARY 23Nitash Balsara, UC Berkeley and Berkeley Lab3:00–4:00 pm Pacific Polymer-Based Lithium Battery Electrolytes and the Pesko Condition Abstract The need for creating safe electrolytes for lithium batteries is significant given the continued safety problems associated with current lithium-ion batteries. Non Flammable polymer electrolytes offer a possible solution but the rate of lithium ion transport is too low for practical applications. In this talk, I will discuss some of the fundamental factors that limit ion transport in polymers. A crucial ingredient in the analysis is a “condition” that my PhD student Danielle Pesko arrived at; I call this the Pesko condition. I will discuss the relevance of this condition on ion transport in polymer electrolytes. Included in the discussion are both homogeneous and nanostructured polymer electrolytes. The responsive nature of nanostructured electrolytes in batteries will be discussed.
Biography Nitash P. Balsara is a chemical engineer with a bachelor’s degree from the Indian Institute of Technology in Kanpur, India in 1982. His graduate education began with a master’s degree from Clarkson University. This was followed by PhD from RPI. After 2 post-docs at the University of Minnesota and Exxon, he joined the faculty of Department of Chemical Engineering at Polytechnic University in Brooklyn. In 2000 he accepted the job that he currently holds: a joint appointment as professor of Chemical Engineering at the University of California, Berkeley and faculty scientist at Lawrence Berkeley National Laboratory. He has managed to hang on to both jobs. Along with his students and collaborators, he cofounded two battery start-ups, Seeo, Inc., and Blue Current. |
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MARCH 9Charlie Bouman, Purdue University3:00–4:00 pm Pacific Emerging Algorithms for CT Imaging of Dynamic Objects After over 40 years, computed tomography is continuing to have a huge impact in scientific, industrial, and medical applications. As scientific researchers push the boundaries of temporal and spatial CT resolution, new reconstruction techniques are required which can produce high image quality with ever more limited data. This talk presents a number of emerging methods in CT imaging that combine specialized acquisition methods with novel reconstruction algorithms to push the technology well beyond traditional limits for the imaging of time-varying objects. In the first application, we present a method for CT reconstruction from ultrasperse view data and show how it can be used to image with nanosecond temporal resolution. Second, we describe a method, called CodEx, that can produce high temporal resolution reconstructions from blurred on-the-fly measurements by imposing a temporal signal code during the acquisition process. Finally, we present a method called multi-slice fusion (MSF) that combines the sensor forward model with a deep neural net prior to produce high quality 4D reconstructions from sparse data. Charles A. Bouman is the Showalter Professor of Electrical and Computer Engineering and Biomedical Engineering at Purdue University. He received his B.S.E.E. degree from the University of Pennsylvania, M.S. degree from the University of California at Berkeley, and Ph.D. from Princeton University in 1989. He is a member of the National Academy of Inventors, a Fellow of the IEEE, AIMBE, IS&T, and SPIE. He is the recipient of the 2021 IEEE Signal Processing Society, Claude Shannon-Harry Nyquist Technical Achievement Award, the 2014 Electronic Imaging Scientist of the Year award, and the IS&T’s Raymond C. Bowman Award; and in 2020, his paper on Plug-and-Play Priors won the SIAM Imaging Science Best Paper Prize. He has served as the IEEE Signal Processing Society’s Vice President of Technical Directions, Editor-in-Chief of the IEEE Transactions on Image Processing, Vice President of Publications for the IS&T Society, and he led the creation of the IEEE Transactions on Computational Imaging. |
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APRIL 13Aashish Manglik, UCSF3:00–4:00 pm Pacific Molecular Puzzles in G Protein-Coupled Receptor Signaling Biography Aashish was an undergraduate at Washington University in St. Louis, where he worked in the lab of Jeff McKinney on Salmonella-host interactions. He moved to California in 2008 to join the Stanford Medical Scientist Training Program. There, he worked with Brian Kobilka as a graduate student to elucidate different aspects of GPCR function, resulting in a number of important contributions to our current understanding of opioid and adrenergic receptors. After finishing his medical training in May 2016, Aashish began his independent research career as the first Stanford Distinguished Fellow at Stanford University School of Medicine within the Department of Molecular and Cellular Physiology. He subsequently began as an assistant professor at UCSF in fall of 2017. |
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APRIL 27Marie D. Jackson, University of Utah3:00–4:00 pm Pacific Reactive Volcanic Tephra and Cementing Processes: From Young Surtsey Tuff to Ancient Roman Concrete The extreme durability of ancient Roman concretes derives from the dynamic behavior over two milennia of mortars fabricated with lime and alkali-rich volcanic tephra. Our experiments at Advanced Light Source Beamline 12.3.2 investigate ancient mortars that bind a self-reinforcing framework of coarse rock and brick aggregate in the concretes of architectural monuments in Rome and marine harbors in the Mediterranean region. Understanding the reaction pathways that have produced the cementitious systems in these mortars and how these evolve over time requires an explicit knowledge of the assemblages of mineral cements in the highly heterogeneous fabrics of the ancient materials. I will describe how powder X-Ray microdiffraction (µXRD) and X-ray microfluorescence (µXRF) experiments at Beamline 12.3.2 and data processing with XMAS software have provided the analytical foundation for describing the mineral cements of intact Roman mortar specimens and basalt specimens from Surtsey volcano, Iceland, the very young geologic analog of the ancient marine concrete. BL 12.3.2 provides a means of precisely mapping variations in the assemblages and crystallographic structures of mineral cements at the micrometer scale while also recording the structure of nanocrystalline phases and their texture, or lattice preferred orientations. The µXRD studies have revealed processes of zeolite (phillipsite) dissolution to produce pozzolanic and post-pozzolanic Al-tobermorite crystals in the ancient seawater concrete, reorganization of calcium-aluminum-silicate-hydrate (C-A-S-H) binder to form a robust nanocrystalline phase with texture in the ancient architectural concrete, and production of authigenic texture in nanocrystalline clay mineral (nontronite) that records biomeditated alteration of basaltic tephra in seawater at Surtsey volcano. The analytical capabilities at BL 12.3.2 could also be instrumental in describing the initiation of cementitious phases in reproductions of the ancient mortars with reactive aggregates produced from recycled glass — thus providing instructive guideposts for applications of Roman geotechnical principles in modern, environmentally-friendly concrete infrastructure. Marie Jackson is a Research Associate Professor in the Department of Geology and Geophysics at University of Utah. Her recent research has focused on the material and mineralogical characteristics of ancient Roman architectural concretes in Rome and marine concretes from harbors in the central and eastern Mediterranean region acquired by the ROMACONS drilling program. She is Principal Investigator of the SUSTAIN drilling project at Surtsey volcano, Iceland, sponsored by the International Scientific Continental Drilling Program. She is also Principal Investigator of a Department of Energy ARPA-E project that explores self-sustaining cementitious systems in reproductions of Roman concretes with reactive glass aggregates. Jackson received a Doctorat d’Université from the Université de Nantes in France and a Ph.D. from Johns Hopkins University in Earth Sciences. She is a fellow of the American Ceramic Society. |
ALS/Molecular Foundry Seminar
FEBRUARY 22Karthish Manthiram, Caltech11:00 am–12:oo pm Pacific Electrification and Decarbonization of Chemical Synthesis Abstract Chemical synthesis is responsible for significant emissions of carbon dioxide worldwide. These emissions arise not only due to the energy requirements of chemical synthesis, but since hydrocarbon feedstocks can be overoxidized or used as hydrogen sources. Using renewable electricity to drive chemical synthesis may provide a route to overcoming these challenges, enabling synthetic routes which operate at benign conditions and utilize sustainable inputs. We are developing an electrosynthetic toolkit in which distributed feedstocks, including carbon dioxide, dinitrogen, water, and renewable electricity, can be converted into diverse fuels, chemicals, and materials. In this presentation, we will first share recent advances made in our laboratory on nitrogen fixation to synthesize ammonia at ambient conditions. Specifically, our lab has investigated a continuous lithium-mediated approach to ammonia synthesis and understood the reaction network that controls selectivity. We have developed non-aqueous gas-diffusion electrodes which lead to high rates of ammonia synthesis at ambient conditions. Then, we will discuss how water can be used as a sustainable oxygen-atom source and how carbon dioxide can be used to achieve carbon chain extension. These findings will be discussed in the context of a broader range of electrosynthetic transformations which could lead to local and on-demand production of critical chemicals and materials. Biography Karthish Manthiram is a Professor of Chemistry and Chemical Engineering at Caltech. The Manthiram Lab is focused on the molecular engineering of electrocatalysts for the synthesis of organic molecules, including pharmaceuticals, fuels, and commodity chemicals, using renewable feedstocks. Karthish received his bachelor’s degree in Chemical Engineering from Stanford University in 2010 and his Ph.D. in Chemical Engineering from UC Berkeley in 2015. After a one-year postdoc at the California Institute of Technology, he joined MIT as an Assistant Professor in 2017. In 2021, he moved to Caltech as a Full Professor of Chemistry and Chemical Engineering. Karthish’s research has been recognized with several awards, including the DOE Early Career Award, NSF CAREER Award, Sloan Research Fellowship, 3M Nontenured Faculty Award, American Institute of Chemical Engineers 35 Under 35, American Chemical Society PRF New Investigator Award, Dan Cubicciotti Award of the Electrochemical Society, and Forbes 30 Under 30 in Science. Karthish’s teaching has been recognized with the Camille Dreyfus Teacher-Scholar Award, C. Michael Mohr Outstanding Undergraduate Teaching Award, the MIT Chemical Engineering Outstanding Graduate Teaching Award, and the MIT Teaching with Digital Technology Award. He serves on the Early Career Advisory Board for ACS Catalysis and on the Advisory Board for Trends in Chemistry. |
Fall 2021 Colloquium Series
SEPTEMBER 29Jeroen van Tilborg, Berkeley Lab3:00–4:00 pm Pacific Plasma-Based Accelerators for Future Light Sources: From High-Brightness Injectors to Driving Compact Free-Electron Lasers Abstract Laser Plasma Accelerators (LPAs), see Refs. [1-2], offer an attractive technology towards production of short (few-fs) and energetic (GeV-class) electron beams. The high-quality LPA e-beam production has spurred the development of unique radiation sources, enabling compactness [3-4] (due to the high accelerating gradient in the plasma), few-fs radiation pulse lengths (from the high-current ultra-short electron bunches), and intrinsic femtosecond synchronization to the drive laser and its secondary products. More specifically, a path towards driving a free-electron laser with LPA electron beams is under investigation at multiple laboratories world-wide, including at LBNL’s BELLA Center. An overview of our efforts will be presented. In parallel to direct compact drivers of light sources, LPAs could also play a critical role as next-generation high-brightness injector for conventional (radio-frequency based) light sources. The rapid injection and ultra-relativistic acceleration inside the plasma environment has the potential to keep the generated high-current electron beam shielded from emittance degradation effects. Therefore, LPAs are being considered to drive future light sources when coupled to conventional accelerator architecture. Basic concepts will be discussed. Acknowledgement: this work was supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231, and by the Gordon & Betty Moore Foundation under Grant ID GBMF4898. [1] T. Tajima and J. M. Dawson, Phys. Rev. Lett. 1979, 43, 267 [2] E. Esarey, C. B. Schroeder, and W. P. Leemans, Rev. Modern Phys. 2009, 81, 1229 [3] T. Gonsalves et al., Phys. Rev. Lett. 2019, 122, 084801 [4] S. K. Barber et al., Appl. Phys. Lett. 2020, 116, 234108 Biography Jeroen van Tilborg is a staff scientist and the Deputy Director for Experiments in the BELLA Center at LBNL. He joined the group in 2009, with research interests covering ultra-intense laser-matter interactions and associated particle and photon production. He received his Ph.D. in Applied Physics from the Eindhoven University of Technology in the Netherlands in 2006, in collaboration with LBNL, for which the APS Division of Physics of Beams awarded him the outstanding thesis award. In 2016 he was granted a DOE Early Career Research Proposal grant, in conjunction with equipment support from the Gordon and Betty Moore Foundation, to make significant advances towards a compact free-electron laser (FEL) based on laser-plasma accelerators (LPAs). |
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OCTOBER 12 *SPECIAL TIME*
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OCTOBER 27Jennifer Doudna, Innovative Genomics Institute @ University of California Berkeley; UCSF/Gladstone Institutes; Howard Hughes Medical Institute3:00–4:00 pm Pacific CRISPR: The Science and Opportunity of Genome Editing Abstract Fundamental research to understand how bacteria fight viral infections uncovered the function
of CRISPR-Cas programmable proteins that detect and cut specific DNA or RNA sequences. I will
describe our research showing how CRISPR-Cas9, an RNA-guided protein, is the foundation of
widely accessible technology for genome editing. Current research focuses on exploring the
biochemical basis for genome editing and developing effective applications in medicine and
agriculture. I will also discuss the development of CRISPR-based diagnostics technology to
address the coronavirus pandemic and improve future preparedness. Finally, I will present
ideas for a future of science that incorporates lessons from the pandemic including
collaboration, teamwork and public access to scientific progress.
Biography Jennifer Doudna, PhD is a biochemist at the University of California, Berkeley. Her groundbreaking development of CRISPR-Cas9 — a genome engineering technology that allows researchers to edit DNA — with collaborator Emmanuelle Charpentier earned the two the 2020 Nobel Prize in Chemistry and forever changed the course of human and agricultural genomics research. She is also the founder and President of the Innovative Genomics Institute, the Li Ka Shing chancellor’s chair in Biomedical and Health Sciences, and a member of the Howard Hughes Medical Institute, Lawrence Berkeley National Lab, Gladstone Institutes, the National Academy of Sciences, and the American Academy of Arts and Sciences. She is a leader in the global public debate on the responsible use of CRISPR and has co-founded and serves on the advisory panel of several companies that use the technology in unique ways. Doudna is the co-author of “A Crack in Creation,” a personal account of her research and the societal and ethical implications of gene editing. |
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NOVEMBER 17 *SPECIAL TIME*Andrea Cavalleri, Max Planck Institute for the Structure and Dynamics of Matter and the University of Oxford10:00–11:00 am Pacific Driven Quantum Materials I will discuss how coherent electromagnetic radiation at Tera-Hertz frequencies can be used to drive quantum solids periodically, leading to non-equilibrium magnetic, ferroelectric and superconducting phases. These ordering phenomena are sometimes observed at temperatures higher than the thermodynamic transition temperatures, due to induced synchronization between otherwise incoherent fluctuations. Andrea Cavalleri is the Founding Director of the Max Planck Institute for the Structure and Dynamics of Matter and a Professor of Physics at the University of Oxford. Before joining the Oxford faculty and becoming a Scientific Member of the Max Planck Society, he was a Scientist in the Materials Sciences Division at LBNL. He is best known for his studies of photo-induced phase transition in strongly correlated electron systems and especially for his work aimed at amplifying functional properties of quantum materials at high temperatures. He has also been active in the general area of femtosecond x-ray science, and has worked with probes generated on tabletops, at synchrotrons and using X-Ray Free Electron Lasers. Cavalleri is a recipient of the Max Born Medal of the IoP and of the Isakson Prize of the APS. |
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DECEMBER 8Erica Saphire, La Jolla Institute for Immunology3:00–4:00 pm Pacific A Global Consortium, Next-Generation SARS-CoV-2 Antibody Therapeutics and Stabilized Spike Erica Ollmann Saphire, Ph.D. is the incoming President and CEO of the nonprofit La Jolla Institute for Immunology. Her research explains, at the molecular level, how and why viruses are pathogenic and provides the roadmap for medical defense. She is best known as the galvanizing force behind the Viral Immunotherapeutic Consortium and Coronavirus Immunotherapeutic Consortium. These international efforts have united dozens of previously competing academic, industrial and government labs across five continents to understand and provide antibody therapeutics against SARS-CoV-2, Ebola, Marburg, Lassa and other viruses. In all these endeavours, she has used molecular insight to bring together scientists and policymakers alike for scientific advancement and social change. Dr. Saphire’s work has been recognized at the White House with the Presidential Early Career Award in Science and Engineering, with young investigator awards from the International Congress of Antiviral Research, the American Society for Microbiology, and the MRC Centre for Virus Research in the United Kingdom. She has also been recognized with an Investigator in the Pathogenesis of Infectious Disease Award from the Burroughs Wellcome Fund, and by the Surhain Sidhu award for the most outstanding contribution to the field of diffraction by a person within five years of the Ph.D. She has been awarded a Fulbright Global Scholar fellowship from the United States Department of State and a Mercator Fellowship from Deutsche Forschungsgemeinschaft, to develop international collaborations around human health and molecular imaging through cryoelectron microscopy and was the 2021 Scientist of the Year of the ARCS Foundation San Diego. |
Summer 2021 Colloquium Series
JUNE 23Jordi Cabana, University of Illinois at Chicago3:00–4:00 pm Using X-rays to Locate Chemical Phenomena in Battery Materials Abstract The evolution of local chemistry determines the performance of electrodes and electrolytes used in batteries because limitations can be tracked to slow kinetics and transport, and irreversibilities in the storage reaction. Tools that provide insight into local chemistry are critical for identifying the underpinnings of electrochemical function. This information must be resolved within architectures, from individual particles to microscale domains, to pinpoint the relationship between local phenomena and their role in macroscopic metrics and degradation. Technical developments in X-ray microscopy and mapping have built a flexible suite of tools that the desired spatial resolution and 3D capabilities with a suite of possible contrasts mechanisms, such as diffraction and spectroscopy. In this talk, we will discuss our recent research that demonstrates the diversity of length scales at which important chemical heterogenity can be induced in battery electrodes. While the focus will be on established Li-ion systems, examples of batteries based on Mg will also be discussed. we will highlight the new fundamental insight generated by the tools, including the prospects of probing time-resolved phenomena using operando measurements. These measurements avoid relaxation of components from the kinetically controlled functional state to one that is more stable under open circuit conditions. The mechanisms of transformation will be related to their impact on material and architecture properties. I will also provide a glimpse into the future by showing how emerging synchrotron techniques can enhance the impact of X-ray microscopy in fundamental battery science. Biography Jordi Cabana is an Associate Professor at the Department of Chemistry of the University of Illinois at Chicago. Prior to his appointment at UIC, he was a Research Scientist at Lawrence Berkeley National Laboratory (USA), from 2008 until 2013. Prof. Cabana completed his Ph.D. in Materials Science at the Institut de Ciència de Materials de Barcelona (Spain) in 2004, and worked in the Department of Chemistry at Stony Brook University (USA) as a postdoctoral associate from 2005 to 2008. He is generally interested in the electrochemistry of inorganic materials, with emphasis on redox and transport properties. |
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JULY 7Naomi Ginsberg, UC Berkeley and Berkeley Lab3:00–4:00 pm How Do Hierarchical Materials Form, Transform, and Transport Energy at the Nanoscale? Abstract Hierarchical materials – materials that include a hierarchy of bonding interactions because their basic building block are more complex than those of individual atoms – present a wide array of underexplored phase behaviors and emergent properties. Examples include many current functional materials comprised of molecules or small particle building blocks, such as glasses and polymer-based plastics in which disorder is deliberately harnessed, and also next-generation semiconductors that can be formed with far more modest protocols than conventional ones, such as those being explored for display technology and solar cells. I will review the basic similarities among and differences between these hierarchical materials’ structure and formation processes and also the emergent properties of various forms of energy transport. One current hallmark of the typical structures of hierarchical materials is that they are often trapped far from equilibrium, presenting heterogeneities that can affect their emergent properties. Studying these materials is therefore best done using a combination of reciprocal-space and direct-space approaches, and I will provide examples of resolving different types of material evolution with each. First, I will describe our transient optical approaches to directly image the nanoscale transport dynamics of various types of quasiparticles in a wide range of hierarchical semiconducting and conducting materials. For example, by characterizing the mean squared expansion of initially localized charge carriers, bound electron-hole pairs, heat, and sound, we elucidate the impact of various material heterogeneities on electronic and thermal transport and also the interplay between heat and charge distributions. Next, many hierarchical materials we study are formed via self-assembly protocols, especially in the solution phase. I will also share recent observations of in situ X-ray scattering of self-assembly and annealing of strongly coupled nanoparticle superlattices. The strong coupling is borne out of the use of short, highly multivalent anionic chalcogenometallates used both as electrolyte anions and stabilizing ligands for the high dielectric nanoparticles, and I will describe our initial work to elucidate the specific mechanisms that drive the assembly and ordering, which could open many possibilities to create hierarchical materials with new functions deterministically from the bottom-up. Biography Naomi S. Ginsberg is an Associate Professor of Chemistry and Physics at University of California, Berkeley and a Faculty Scientist in the Materials Sciences and Molecular Biophysics and Integrated Imaging Divisions at Lawrence Berkeley National Laboratory, where she has been since 2010. She currently focuses on elucidating the electronic and molecular dynamics in a wide variety of soft electronic and biological materials by devising new electron and optical imaging modalities that enable characterization of fast and ultrafast processes at the nanoscale and as a function of their heterogeneities. Naomi received a B.A.Sc. degree in Engineering Science from the University of Toronto in 2000 and a Ph.D. in Physics from Harvard University in 2007, after which she held a Glenn T. Seaborg Postdoctoral Fellowship at Lawrence Berkeley National Lab. Her background in chemistry, physics, and engineering has previously led her to observe initiating events of photosynthesis that take place in a millionth billionth of a second and to slow, stop, and store light pulses in some of the coldest atom clouds on Earth. She is the Berkeley lead of STROBE, a multi-university NSF Science and Technology Center devoted to imaging science, a member of the Kavli Energy Nanoscience Institute at Berkeley, and the recipient of a David and Lucile Packard Fellowship in Science and Engineering (2011), a DARPA Young Faculty Award (2012), an Alfred P. Sloan Foundation Fellowship (2015), and a Camille Dreyfus Teacher-Scholar Award (2016) in addition to a series of teaching awards in the physical sciences. In 2017-18 she was a Miller Professor for Basic Research in Science at UC Berkeley and was designated a Kavli Fellow. In 2019 she was the Kroto Lecturer in Chemical Physics at Florida State University. She is the recipient of the 2020 ACS Early-Career Award in Experimental Physical Chemistry. |
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JULY 21Claudia Felser, Max Planck Institute for Chemical Physics of Solids3:00–4:00 pm Topology and Chirality Abstract Topology, a mathematical concept, recently became a hot and truly transdisciplinary topic in condensed matter physics, solid state chemistry and materials science. All 200 000 inorganic materials were recently classified into trivial and topological materials: topological insulators, Dirac, Weyl and nodal-line semimetals, and topological metals [1]. The direct connection between real space: atoms, valence electrons, bonds and orbitals, and reciprocal space: bands and Fermi surfaces allows for a simple classification of topological materials in a single particle picture. More than 25% of all inorganic compounds host topological bands, which opens also an infinitive play-ground for chemistry [1,2]. Beyond Weyl and Dirac, new fermions can be identified in compounds that have linear and quadratic 3-, 6- and 8- band crossings that are stabilized by space group symmetries [3]. Crystals of chiral topological materials CoSi, AlPt and RhSi were investigated by angle resolved photoemission and show giant unusual helicoid Fermi arcs with topological charges (Chern numbers) of ±2 [4]. In agreement with the chiral crystal structure two different chiral surface states are observed. A qunatized circular photogalvanic effect is theoretically possible in Weyl semimetals. However, in the multifold fermions with opposite chiralities where Weyl points can stay at different energies, a net topological charge can be generated. This net topological charge can lead to a quantized signal in the circular polarized light-induced injection current, if trivial bands are not to dominant at EF [5]. However, chirality is also of interest for chemists [6], especially because of the excellent catalystic performance of the new chiral Fermions AlPt and PdGa [7]. The open question is the interplay between Berry curvature, chirality, orbital moment and surface states.
Biography Claudia Felser studied chemistry and physics at the University of Cologne (Germany, completing there both her diploma in solid state chemistry (1989) and her doctorate in physical chemistry (1994). After postdoctoral fellowships at the Max Planck Institute in Stuttgart (Germany) and the CNRS in Nantes (France), she joined the University of Mainz (Germany) in 1996 becoming a full professor there in 2003. She is currently Director at the Max Planck Institute for Chemical Physics of Solids in Dresden (Germany). Her research foci are the design and discovery of novel inorganic compounds, in particular, Heusler compounds for multiple applications and new topological quantum materials. In 2011 and again in 2017, she received an ERC Advanced grant. Felser was honored as a Distinguished Lecturer of the IEEE Magnetics Society, she received the Alexander M. Cruickshank Lecturer Award of the Gordon Research Conference, a SUR-grant Award from IBM and the Tsungmin Tu Research Prize from the Ministry of Science and Technology of Taiwan, the highest academic honor granted to foreign researchers in Taiwan. In 2019, Claudia Felser was awarded the APS James C. McGroddy Prize for New Materials together with Bernevig (Princeton) and Dai (Hongkong). She is a Fellow of the American Physical Society and the Institute of Physics, London. In 2018, she became a member of the Leopoldina, the German National Academy of Sciences, and acatech, the German National Academy of Science and Engineering. In 2020, she became an international member of the National Academy of Engineering, and in 2021, she became an international member of the National Academy of Sciences. |
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AUGUST 4Alexander Gray, Temple University3:00–4:00 pm Synergies between Synchrotron and Lab-based X-ray Techniques for the Studies of Complex Materials and Interfaces Photoemission spectroscopy is a powerful and well-established experimental technique for probing the electronic structure of matter. In this talk, I will discuss several promising new directions in this field, which stem from experimental and theoretical studies wherein photoemission experiments are carried out at higher excitation energies and in tandem with other complementary synchrotron and lab-based x-ray techniques. I will focus specifically on the recent studies of novel engineered quantum materials and heterostructures, which aim at gaining a clear understanding of the depth-dependent nanoscale evolution of materials’ electronic properties at the surface, in the bulk, and across the buried interfaces by using multiple modalities of hard and soft x-ray photoemission both separately and in concert with each other. Alexander Gray is an Assistant Professor of Physics at Temple University. He received his Ph.D. in Physics from the University of California Davis, and then did his postdoctoral training at Stanford University and SLAC National Accelerator Laboratory. Prof. Gray’s group’s research activities focus on the development of novel depth- and time-resolved x-ray spectroscopic and scattering techniques for studying rich electronic behaviors in quantum solids and interfaces. He has been awarded a Young Investigator Program award by the Department of Defense, and the Early Career Award by the Department of Energy. |
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AUGUST 18Pantaleo Raimondi, SLAC3:00–4:00 pm Beyond EBS Dr. Pantaleo Raimondi has been the ESRF’s Accelerator & Source Director and is now a professor at SLAC. He obtained his PhD in 1986 at the Bari University, Italy and received the Gersh Budker Prize of the European Physical Society in 2017 for his invention of the Hybrid Multi Bend Achromat (HMBA) lattice which has become the design basis of 4th generation synchrotron sources. He led the ESRF-Extremely brilliant source (EBS) project to successful completion in 2020. Dr. Raimondi has a long and rich experience in research and development at accelerators including SLAC, CERN, ENEA and INFN where he gained a deep knowledge of accelerator design and commissioning, from the development of RF power systems, microtrons and linacs to the operation, design and realization of circular and linear colliders. Dr. Raimondi is also the recipient of two IPAC awards and contributed to over 300 publications over the span of his career. |
UEC Seminar Series: Science Enabled by ALS-U
APRIL 2Hélio C. N. Tolentino, Brazilian Synchrotron Light Laboratory (LNLS)12:10–1:00 pm Science Program Using Coherent X-Rays at the Sirius-LNLS Synchrotron Source I will show a brief overview of the Sirius source connected to the IDs for delivering highly coherent X-rays and an overview of the beamlines that are somehow developing techniques related to use of coherence. I will then present the science areas that we are planning to tackle and the local infrastructure that have been developed. Helio Tolentino has been a researcher at the Brazilian Synchrotron Light Laboratory (LNLS), one of the national labs of the Brazilian Center for Research in Energy and Materials (CNPEM) in Campinas, SP, Brazil, since 2014. He has also served as Head of the Heterogeneous and Hierarchical Matter Division (DMH) of the LNLS since 2020. Since 2015, he has coordinated the project and construction of the Carnaúba (X-ray nanoprobe) beamline for the new Brazilian synchrotron light source, Sirius. Its main research interests are in the physics and chemistry of condensed matter systems, with emphasis in heterogeneous and hierarchical materials for energy and photonics, and in the development of synchrotron radiation instrumentation for the study of several materials at the nanoscale. |
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MAY 7Maik Kahnt, MAX IV (Sweden)12:10–1:00 pm Ptychography – Coherence and Nano Beams New 4th generation light sources offer a larger coherent fraction of the beam compared to their predecessors. X-ray microscopy based on ptychography is one of the methods which should benefit most from this increase. In this talk I will briefly introduce the method itself, describe its requirements / limitations, present exemplary science cases and finally explore how the method scales (how to see more, better and in a shorter time) while discussing how these additional coherent photons can be used at the latest generation of light sources. Maik Kahnt is a beamline scientist (previously postdoc) at the NanoMAX beamline (MAX IV, Lund, Sweden). Before coming to Sweden in 2019 he worked in the “X-Ray Nanoscience and X-Ray Optics” group at PETRA III (DESY) on X-ray microscopy methods, X-ray optics characterization and development of algorithms for coherent imaging techniques. In Sweden he continues his work on 3D X-ray microscopy and ptychographic methods to characterize both the sample and the properties of the probing beam. His main research interest is the development and improvement of the methods used to answer the users specific questions and advance the users science cases. |
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June 4Claire Donnelly, University of Cambridge and Cavendish Laboratory (UK)Time: 9:00–10:00 am Coherent X-Ray Imaging of 3D Magnetic Systems Three dimensional magnetic systems promise significant opportunities for applications, for example providing higher density devices and new functionality associated with complex topology and greater degrees of freedom [1,2]. For the experimental realisation of these new properties, appropriate characterisation techniques are required to determine both the three-dimensional magnetic structure, and its response to external excitations. In this talk, I will describe how we have made use of coherent X-rays to characterize the three-dimensional structure of magnetic systems at the nanoscale. In particular, we have developed X-ray magnetic nanotomography [3] to access the three-dimensional magnetic configuration at the nanoscale. In a first demonstration, we have determined the complex three-dimensional magnetic structure within the bulk of a micrometre-sized soft magnetic pillar and observed a magnetic configuration that consists of vortices and antivortices, as well as Bloch point singularities [3]. In addition to the static magnetic structure, the dynamic response of the 3D magnetic configuration to excitations is key to our understanding of both fundamental physics, and applications. With our recent development of X-ray magnetic laminography [4,5], it is now possible to determine the magnetisation dynamics of a three-dimensional magnetic system [5] with spatial and temporal resolutions of 50 nm and 70 ps, respectively. A final challenge concerns the identification of nanoscale topological objects within the complex reconstructed magnetic configurations. To address this, we have recently implemented calculations of the magnetic vorticity [6,7], that make possible the location and identification of 3D magnetic solitons, leading to the first observation of magnetic vortex rings [7]. These new experimental capabilities of X-ray magnetic imaging open the door to the elucidation of complex three-dimensional magnetic structures, and their dynamic behaviour. In the coming years, 3D magnetic imaging will benefit significantly from advances in synchrotron radiation, with associated increases in coherent flux leading to higher spatial resolutions, as well as higher throughput for in situ measurements. |
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July 23Joshua Turner, Stanford Institute for Materials and Energy SciencesTime: 12:15–1:15 pm Coherent X-ray Scattering at ‘Fast’ Timescales With the development of next-generation coherent X-ray Free Electron Laser (X-FEL) sources, we are entering a new regime to study fluctuations at ‘fast’ timescales in quantum materials. In this talk, we will define what ‘fast’ is and we will discuss recent results on the measurement of fluctuations in complex magnetic materials, the so-called ‘skyrmion’ crystal. These results demonstrate that the tools we have been developing can now be used to understand stochastic processes near phase transitions in many types of materials, offering access to understanding the interactions within solids. These studies, which are based on using ultrafast pulses together with newly developed modes from the X-FEL at the SLAC National Accelerator Laboratory, also provide a roadmap for future studies using coherence in the area of quantum materials. Joshua Turner is a staff scientist at the Stanford Institute for Materials and Energy Sciences, a joint institute between Stanford University and SLAC National Accelerator Laboratory, as well as at the Linac Coherent Light Source, an x-ray free electron (XFEL) which is based at SLAC. He is a leader in ultra-fast x-ray studies, which he has applied to an array of scientific fields, from chemistry and materials physics to the study of plasmas found in large planets and hot astrophysical objects. His most recent focus is on an innovative technology which utilizes new modes of the XFEL and can be used to study subtle fluctuations in materials using short, coherent x-ray pulses. This will advance the frontier in quantum materials through the observation of novel types of order found in exotic systems such as topological magnets, unconventional superconductors, and strongly spin-orbit coupled Mott insulators. He has published over 100 scientific articles. |
ALS/Molecular Foundry Seminar
JUNE 8Clare Grey (University of Cambridge)11:00 am – 12:00 pm New Tools for Tracking Battery Function and Failure – Applications to Small, Big, and Faster Charging Batteries Optimisation of battery performance (e.g., rate and lifetime) requires that we understand how battery materials function under operating conditions. This talk will describe the development and application of new approaches to understand both traditional lithium ion chemistry and beyond “Li-ion” technologies – including redox flow batteries. The Grey group studies the nature of solid state materials by nuclear magnetic resonance (NMR), X-ray and Neutron scattering, electron microscopy and computational calculations. The materials we investigate have applications in supercapacitors, fuel cells, and batteries. Our current research projects are described here and a full list of publications is available here. We currently have 49 group members including 3 Master students, 22 PhD students (11 students being co-supervised) and 21 Post-Doctoral researchers all listed here. The group is very dynamic and also very international with almost 20 nationalities represented. |
Winter 2020 Colloquium Series
FEBRUARY 19Michal Bajdich, SLAC National Laboratory3:00–4:00 pm, Room 15-253 Computational Catalysis and Machine Learning for Sustainable Energy Abstract Fueling the planet with clean and sustainable energy is one of the central challenges of the 21st century. At the center of these technologies are energy transformations facilitated by catalytic processes. The largest breakthrough is needed in the electrochemical catalysis of water, oxygen and CO2 reduction, where the active, stable, and earth-abundant catalysts are yet to be discovered. In my talk, I will discuss latest approaches developed at the SUNCAT Center, SLAC to address the above challenges. Particularly, I will highlight the role of theory in explaining the mechanism of reduction of CO2 to CO in Solid-Oxide Fuel-Cells [1], as observed by operando-XPS performed at ALS (see also ALS News: https://als.lbl.gov/new-catalyst-resists-destructive-carbon-buildup-in-electrodes/). Next, I will show how theory can leads us to understanding the local coordination environments of single-atom catalysts recently observed by in situ electrochemical cell XAS. Both, the experimental and theoretical challenges remain in the identification of active phases and mechanisms under reaction conditions. For that reason, I will show how Active Machine Learning applied to a bulk prototype space can lead to accelerated discovery of stable and active phases and how catalysis research efforts across the globe can by scaled-up with our computational catalysis repository: Catalysis-hub.org [2]. [1] Skafte, T. L.; Guan, Z.; Machala, M. L.; Gopal, C. B.; Monti, M.; Martinez, L.; Stamate, E.; Sanna, S.; Garrido Torres, J. A.; Crumlin, E. J; Bajdich, M.; Chueh, W., Graves, C.; Selective High-Temperature CO2 Electrolysis Enabled by Oxidized Carbon Intermediates. Nat. Energy 2019, 1–10. https://doi.org/10.1038/s41560-019-0457-4. [2] Winther, K. T.; Hoffmann, M. J.; Boes, J. R.; Mamun, O.; Bajdich, M.; Bligaard, T. Catalysis-Hub.Org, an Open Electronic Structure Database for Surface Reactions. Sci. Data 2019, 6 (1), 75. https://doi.org/10.1038/s41597-019-0081-y.Biography Dr. Michal Bajdich started his career in 2009 as the Postdoctoral Fellow, Materials Theory Group, Oak Ridge National Laboratory, where he worked on quantum Monte Carlo methods for accurate electronic structure calculations and general supercomputing applications. In 2011, he moved to Lawrence Berkeley National Laboratory to be part of the Joint Center for Artificial Photosynthesis—center with the goal of creating solar fuels— where his is involved to present day. Since 2013, Dr. Bajdich has been a part of the SUNCAT Center for Interface Science and Catalysis at SLAC National Accelerator Laboratory and Department of Chemical Engineering at Stanford University. Dr. Bajdich is interested in the application of ab-initio computational methods for understanding and discovery of electrocatalysis, with special focus on earth-abundant metal-oxides and related materials. He also works on the development of theoretical models for electrochemistry and XAS spectroscopy. Recently, he started applying catalysis informatics and machine learning tools to catalysts discovery. He is an author of more than 60 publications, 2 book chapters, and his work received more than +4000 citations. He is a co-founder of Catalysis-hub.org and a member of AICHE programming committee, and many of other professional societies. Dr. Bajdich has received his Ph.D. in Physics in 2007 from North Carolina State University, USA. He earned his master’s degree in Physics, Comenius University, Bratislava, Slovakia. |
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FEBRUARY 26Jordi Cabana, University of Illinois at Chicago3:00–4:00 pm, Room 15-253 Advances in X-Ray Microscopy for the Study of Battery Reactions in Single Particles Abstract The existing performance limitations of Li-ion batteries can be tracked to slow kinetics and irreversibilities in the chemical changes undergone by the electrode materials.Tools that provide insight into the onset and propagation of these transitions are critical for identifying the underpinnings of electrochemical function.This information must be generated at the nanoscale because reaction kinetics and irreversibilities at the level of individual particles determine macroscopic metrics and trigger architecture degradation, respectively.Synchrotron-based X-ray microscopy currently combines nanoscale spatial resolution with a suite of possible contrasts mechanisms, such as diffraction and spectroscopy.In this talk, I will discuss recent research geared toward the chemical imaging of electrochemical reactions in battery electrodes, focusing on single particles. While the focus will be on established Li-ion systems, examples of batteries based on Mg will also be discussed. I will highlight the new fundamental insight generated by the tools, including time-resolved phenomena using operando measurements. These measurements avoid relaxation of components from the kinetically controlled functional state to one that is more stable under open circuit conditions. The mechanisms of transformation will be related to their impact on material and architecture properties. I will also provide a glimpse into the future by showing how emerging synchrotron techniques can enhance the impact of X-ray microscopy in fundamental battery science. Biography Jordi Cabana is an Assistant Professor at the Department of Chemistry of the University of Illinois at Chicago. Prior to his appointment at UIC, he was a Research Scientist at Lawrence Berkeley National Laboratory (USA), from 2008 until 2013. Prof. Cabana completed his Ph.D. in Materials Science at the Institut de Ciència de Materials de Barcelona (Spain) in 2004, and worked in the Department of Chemistry at Stony Brook University (USA) as a postdoctoral associate. He is generally interested in the electrochemistry of inorganic materials, with emphasis on redox and transport properties. |
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MARCH 11Claudia Felser, Max Planck Institute for Chemical Physics of Solids3:00–4:00 pm, Room 15-253 Magnetic Weyl Semimetals! Abstract Claudia Felser1, Kaustuv Manna1, Enke Lui1 and Yan Sun1 1Max Planck Institute Chemical Physics of Solids, Dresden, Germany (e-mail: felser@cpfs.mpg.de) Topology a mathematical concept became recently a hot topic in condensed matter physics and materials science. One important criteria for the identification of the topological material is in the language of chemistry the inert pair effect of the s-electrons in heavy elements and the symmetry of the crystal structure [1]. Beside of Weyl and Dirac new fermions can be identified compounds via linear and quadratic 3-, 6- and 8- band crossings stabilized by space group symmetries [2]. In magnetic materials the Berry curvature and the classical AHE helps to identify interesting candidates. Magnetic Heusler compounds were already identified as Weyl semimetals such as Co2YZ [3,4], in Mn3Sn [5,6,7] and Co3Sn2S2 [8-10]. The Anomalous Hall angle helps to identify even materials in which a QAHE should be possible in thin films. Besides this k-space Berry curvature, Heusler compounds with non-collinear magnetic structures also possess real-space topological states in the form of magnetic antiskyrmions, which have not yet been observed in other materials [11]. [1] Bradlyn et al., Nature 547 298, (2017) arXiv:1703.02050 [2] Bradlyn, et al., Science 353, aaf5037A (2016). [3] Kübler and Felser, Europhys. Lett. 114, 47005 (2016) [4] I. Belopolski, et al., Science in print (2019), arXiv:1712.09992 [5] Kübler and Felser, EPL 108 (2014) 67001 (2014) [6] Nayak, et al., Science Advances 2 e1501870 (2016) [7] Nakatsuji, Kiyohara and Higo, Nature 527 212 (2015) [8] Liu, et al. Nature Physics 14, 1125 (2018) [9] D. F. Liu, et al., Science in print (2019) [10] N. Morali, et al., Science in print (2019) arXiv:1903.00509 [11] Nayak, et al., Nature 548, 561 (2017) Biography Claudia Felser studied chemistry and physics at the University of Cologne (Germany, completing there both her diploma in solid state chemistry (1989) and her doctorate in physical chemistry (1994). After postdoctoral fellowships at the Max Planck Institute in Stuttgart (Germany) and the CNRS in Nantes (France), she joined the University of Mainz (Germany) in 1996 becoming a full professor there in 2003. She is currently Director at the Max Planck Institute for Chemical Physics of Solids in Dresden (Germany). Her research foci are the design and discovery of novel inorganic compounds, in particular, Heusler compounds for multiple applications and new topological quantum materials. In 2011 and again in 2017, she received an ERC Advanced grant. Felser was honored as a Distinguished Lecturer of the IEEE Magnetics Society, she received the Alexander M. Cruickshank Lecturer Award of the Gordon Research Conference, a SUR-grant Award from IBM and the Tsungmin Tu Research Prize from the Ministry of Science and Technology of Taiwan, the highest academic honor granted to foreign researchers in Taiwan. In 2019, Claudia Felser was awarded the APS James C. McGroddy Prize for New Materials together with Bernevig (Princeton) and Dai (Hongkong). She is a Fellow of the American Physical Society and the Institute of Physics, London. In 2018, she became a member of the Leopoldina, the German National Academy of Sciences, and acatech, the German National Academy of Science and Engineering. |
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**TUESDAY** MARCH 17Sayeef Salahuddin, UC Berkeley**4:00–5:00 pm**, Room 15-253 Negative Capacitance, Ultra-thin Ferroelectrics and Applications Abstract The physics of ordered and correlated systems allows for fundamental improvement of energy consumption, going beyond what is possible with conventional materials. One such example is the class of materials with polar distortion such as a (anti)ferroelectric, where thermodynamics dictate that charge can be switched with much lower energy compared to conventional dielectrics. In these materials the internal order leads to a state of negative capacitance, which results in a boost of internal electric fields and charge. This boost could be exploited for reducing energy dissipation in electronics. In this talk, I shall discuss our current understanding of negative capacitance derived from experimental demonstration of steady state negative capacitance, which allows one to access an otherwise forbidden part of the energy landscape in ferroelectric materials. The discovery of HfO2 based ferroelectrics has enabled the integration of ferroelectric materials onto Si in a process compatible way. This makes it possible to achieve negative capacitance transistors. I shall discuss some of our most recent transistor work. To be used in most advanced transistors, ferroelectric materials will need to scaled down below 20A in thickness. Some results on such extremely thin FE materials will also be presented. Biography S. Salahuddin is the TSMC Distinguished Professor of Electrical Engineering and Computer Sciences at the University of California Berkeley. His work has focused mostly on conceptualization and exploration of novel device physics for low power electronic and spintronic devices. Salahuddin has received the Presidential Early Career Award for Scientist and Engineers (PECASE). Salahuddin also received a number of other awards including the NSF CAREER award, the IEEE Nanotechnology Early Career Award, the Young Investigator Awards from (AFOSR) and (ARO), and the IEEE George E Smith Award. Salahuddin is a co-director of the Berkeley Device Modeling Center (BDMC) and Berkeley Center for Negative Capacitance Transistors (BCNCT). Salahuddin is also a co-director of ASCENT, one of the six centers of the JUMP initiative sponsored by SRC/DARPA. He served on the editorial board of IEEE Electron Devices Letters (2013-16) and was the chair of the IEEE Electron Devices Society committee on Nanotechnology (2014-16). Salahuddin is a Fellow of the IEEE and the APS. |
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APRIL 1Kristen Hunter-Cevera, Marine Biological Laboratory3:00–4:00 pm, Room 15-253 Ecological Dynamics of a Marine Cyanobacteria Population Marine picocyanobacteria are key players in both open ocean and coastal waters. These organisms are numerically dominant and responsible for up to a quarter of marine primary production, and it is important to understand the factors, both abiotic and biotic, that affect their abundance and activity. Here we present insights into the dynamics of a coastal Synechococcus population on the U.S. Northeast Shelf. This population has been monitored with high resolution, automated flow cytometry since 2003, and the resulting 16-year time series has provided novel understanding into the environmental and biological controls on this population. These dynamics, however, result from a diverse Synechococcus assemblage, comprised of multiple, distinct strains that differ in their ecophysiologies and relative abundances. We explore these field observations with laboratory investigations of cultured isolates, and in particular focus on interactions with heterotrophic protist grazers and associated bacteria. We have begun to explore the latter with synchrotron radiation-based Fourier transform infrared (sFTIR) spectromicroscopy at the ALS, enabling us to gather valuable chemical information about cellular components. Kristen Hunter-Cevera is currently a Hibbitt Early Career Fellow at the Marine Biological Laboratory in Woods Hole, Massachusetts. She is interested in microbial ecology and specifically how environmental variables, species interactions and underlying diversity structure affect microbial community dynamics, activity and stability. Her research focuses on the marine cyanobacterium Synechococcus as a model to explore these questions with a combination of field observations, laboratory culture experiments and modeling. She received a B.S. in biology and mathematics in 2008, and an M.B.A. in 2009 from West Virginia University. She earned a Ph.D. in biological oceanography from the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in 2014 with a National Defense Science and Engineering Graduate Fellowship, and is currently a Simons Early Career Investigator in Marine Microbial Ecology and Evolution. |
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APRIL 8Alexander Gray, Temple University3:00–4:00 pm, Room 15-253 Synergies between Synchrotron and Lab-based X-ray Techniques for the Studies of Complex Materials and Interfaces Photoemission spectroscopy is a powerful and well-established experimental technique for probing the electronic structure of matter. In this talk, I will discuss several promising new directions in this field, which stem from experimental and theoretical studies wherein photoemission experiments are carried out at higher excitation energies and in tandem with other complementary synchrotron and lab-based x-ray techniques. I will focus specifically on the recent studies of novel engineered quantum materials and heterostructures, which aim at gaining a clear understanding of the depth-dependent nanoscale evolution of materials’ electronic properties at the surface, in the bulk, and across the buried interfaces by using multiple modalities of hard and soft x-ray photoemission both separately and in concert with each other. Alexander Gray is an Assistant Professor of Physics at Temple University. He received his Ph.D. in Physics from the University of California Davis, and then did his postdoctoral training at Stanford University and SLAC National Accelerator Laboratory. Prof. Gray’s group’s research activities focus on the development of novel depth- and time-resolved x-ray spectroscopic and scattering techniques for studying rich electronic behaviors in quantum solids and interfaces. He has been awarded a Young Investigator Program award by the Department of Defense, and the Early Career Award by the Department of Energy. |
Fall 2019 Colloquium Series
Summer 2019 Colloquium Series
Spring 2019 Colloquium Series
APRIL 17David Kisailus, UC Riverside3:00–4:00 pm, Room 15-253 Biologically Inspired Multi-Functional Materials Abstract
With an alarming global population increase, there is a critical need for the development of multifunctional strong and tough lightweight materials for use in many societal applications. Natural systems have evolved efficient strategies, exemplified in the biological tissues of numerous animal and plant species, to synthesize and construct composites from a limited selection of available starting materials that often exhibit exceptional mechanical properties that are similar, and frequently superior to, mechanical properties exhibited by many engineering materials. Nature goes one step further, often producing materials with that display multi-functionality in order to provide organisms with a unique ecological advantage to ensure survival.
In this work, we investigate organisms that have adapted structures, which are not only strong and tough, but also demonstrate multifunctional features dependent on the underlying organic-inorganic components. We are utilizing additive manufacturing methods to help validate hypotheses based on our experimental observations as well as translate key mechanistic insights to scalable and manufacturable engineered products. Furthermore, we discuss strategies for synthesis of these bio-composites, by studying for example, the heavily crystallized radular teeth the chitons, a group of elongated mollusks that graze on hard substrates for algae. From the investigation of synthesis-structure-property relationships in these unique organisms, we are now developing and fabricating cost-effective and environmentally friendly multifunctional engineering composites and biologically inspired nanomaterials for energy conversion and storage. Biography Prof. David Kisailus is the Associate Vice Chancellor of Research Facilities, the Winston Chung Endowed Chair of Energy Innovation and Professor in the Materials Science and Engineering Program and the Department of Chemical and Environmental Engineering at the University of California at Riverside. Dr. Kisailus, a Kavli Fellow of the National Academy of Sciences and a UNESCO Chair in Materials and Technologies for Energy Conversion, Saving and Storage, received his Ph.D. in Materials from the University of California at Santa Barbara, 2002; M.S. in Materials Science (University of Florida) and B.S. in Chemical Engineering (Drexel University). Dr. Kisailus was a post-doctoral researcher in Molecular Biology at UCSB and a Research Scientist at HRL Laboratories working on synthesis of materials for fuel cells and batteries. His “Biomimetic and Nanostructured Materials Laboratory” investigates fundamental synthesis – structure – property relationships in biological composites, with unique mechanical, thermal and optical properties, in order to develop multifunctional light-weight, tough and impact resistant materials as well as develop / utilize solution-based processes to synthesize nanoscale materials for energy-based applications. The ultimate goal is to be able to leverage lessons from Nature to develop next generation materials for energy conversion and storage as well as for environmental applications. |
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APRIL 24Pupa Gilbert, University of Wisconsin–Madison3:00–4:00 pm, Room 15-253 How Organisms Build Crystals Abstract Crystalline biominerals cost energy but provide the diverse organism making them with scaffolding, shielding, locomotion, mastication, gravity and magnetic field sensing, etc. How these crystals are formed reveals how living organisms harness the laws of physics and chemistry for their evolutionary advantage, but also because it can teach us new synthesis strategies for materials with targeted properties. Recent synchrotron spectromicroscopy methods reveal one formation mechanism and one toughening mechanism:
Biography Pupa Gilbert got her doctoral degree in Physics in 1987 in Rome, Italy. She was a staff scientist at the Italian CNR and the EPFL before coming to the US as a professor of physics at UW-Madison in 1999. She is a physicist with a burning passion for biology and materials science, and she studies natural biominerals, their structure, and formation mechanisms with the synchrotron spectromicroscopy methods she developed, and for which she won the 2018 Shirley award for outstanding scientific achievement at the ALS. |
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MAY 1Abby Kavner, UCLA3:00–4:00 pm, Room 6-2202 The Electrochemical Planet: Phase Stability and Equations of State for Metals and Oxides at the High Pressure and Temperatures of Earth’s Interior Abstract The boundary between the Earth’s metal core and oxide mantle plays an important role in thermal, mechanical and chemical evolution of planet. The thermodynamics of core and mantle materials at high pressure and temperature conditions govern which elements tend to be oxidized in the mantle and which tend to be reduced, forming the core. In this talk, I will show how synchrotron-based X-ray diffraction methods can be used to help determine phase stability and measure thermoelastic properties of metals, oxides, and carbonates at the extreme conditions relevant to the interior of the planet. The goal is to extend the electrochemical series to extreme conditions of planetary interiors. Biography Professor Kavner’s love for geosciences developed during summers spent camping, hiking, and canoeing throughout the northeast. She studied materials science and engineering at Northwestern University (B.S. 1989) and at UC Berkeley (M.S.E 1993). At that point she discovered the great materials science problems posed by Earth science, and switched fields, to Geophysics at UC Berkeley (Ph.D. 1997). She has been collecting data at various synchrotron sources since encountering her first empty hutch in 1995. After postdoctoral stints at Princeton and Lamont Doherty Earth Observatory, she has been a faculty member at UCLA since 2002. |
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MAY 8Michael Odelius, Stockholm University3:00–4:00 pm, Room 6-2202 Hydrogen Bonding and Ultra-Fast Dynamics—Ab Initio Modeling of Resonant Inelastic X-Ray Scattering Abstract It is important to acquire detailed molecular information on hydrogen bonding, which determines the properties of liquid water and the outcome of many biochemical processes. Quantum chemical calculations and x-ray spectroscopy form naturally complementary techniques for investigation of hydrogen bonding and the influence on the electronic structure. Different levels of theoretical analysis will be discussed in the presentation. The work benefits greatly from experiments at Beamline 8.0.1 at ALS, where x-ray emission measurements of liquid water and aqueous solutions have been performed and have been analysed in terms of ab initio molecular dynamics simulations and spectrum simulations. https://als.lbl.gov/wp-content/uploads/2016/09/actrep2005.pdf https://als.lbl.gov/exploring-structure-aqueous-solutions-salsa/ The recent development of ultrahigh-resolution resonant inelastic x-ray scattering (RIXS) has, in combination with quantum mechanical simulations, allowed us to analyze highly excited vibrational quanta in liquid water, giving a clue as to how hydrogen bonding influences the long-range region of O-H potentials in the liquid. In addition, we have shown that high-level quantum chemical calculations can be used for modeling RIXS of valence-excited species and simulating excited state dynamics, which allows us to assist in the interpretation of time-resolved x-ray spectra to determine the pathways of photo-induced processes. Biography Michael Odelius is a professor in theoretical chemical physics at Stockholm University. He received his Ph.D. in physical chemistry at Stockholm University in 1994 working on simulations on nuclear spin relaxation, measured with radio waves. His interest has now turned to the other end of the electromagnetic spectrum, and he is working on simulations of X-ray spectra and of ultra-fast chemical processes. He was a post-doctoral researcher in the group of Michele Parrinello the Max Planck Institute for Solid State Research in Stuttgart and in the group of Jürg Hutter at the University of Zurich. Combining ab initio molecular dynamics and multi-configurational quantum chemical calculations, he studies the interplay between electronic structure, inter-molecular interactions and dynamics in hydrogen bonded liquids and in photo-induced processes. |
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MAY 15Jyoti Katoch, Carnegie Mellon University3:00–4:00 pm, Room 15-253 Unraveling the Novel Quantum Phenomena in Two-Dimensional Materials Using Transport and Photoemission Spectroscopy Abstract The extreme surface sensitivity of two-dimensional (2D) materials provides an unprecedented opportunity to engineer the physical properties of these materials via changes to their surroundings, including substrate, adsorbates, defects, etc. In addition, 2D materials can be mechanically assembled layer-by-layer to form vertical or lateral heterostructures, making it possible to create new material properties merely by the choice of the constituting 2D layers and the relative twist angle between them. In this talk, I will discuss our recent transport [1] and photoemission [2] results that shed light on the intricate relationship between controlled external perturbations, substrate, and electronic properties of 2D materials. I will show that the decoration of the 2D materials with adatoms, such as sub-lattice selective atomic hydrogenation of graphene and alkali metal doping of single layer WS2 can be utilized to tailor electronic properties and induce novel quantum phenomena in 2D landscape. [1] Katoch et. al., Physical Review Letters 121, 136801 (2018). [2] Katoch et. al., Nature Physics 14, 355-359 (2018).Biography Jyoti Katoch grew up in Chandigarh, India and received her Ph.D. in physics from University of Central Florida in 2014. She held a postdoctoral appointment at the Ohio State University from 2014-2016 and as research scientist from 2016-2018. She recently joined the physics department at the Carnegie Mellon University as an assistant professor in fall 2018. |
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MAY 22Stephan Roth, Deutsches Elektronen-Synchrotron (DESY)3:00–4:00 pm, Room 6-2202 Challenges in Grazing-Incidence Small-Angle X-Ray Scattering (GISAXS) Abstract In situ and operando studies in thin film technologies are crucial ingredients for elucidationg the nanostructural evolution during fabrication and operation of thin film devices, as the nanostructure governs the macroscopic properties. Hence, grazing incidence small-angle (and wide angle) X-ray scattering has developed into a vital advanced method in this field. To sketch this development, I present highlight examples from coating technologies, namely spray-coating and physical vapor deposition [1,2], both of which are heavily used in thin film technology and roll-to-roll coating. In combination with biomaterials, new routes for organic electronics become possible [3]. Challenges involved are the high data rates during the in situ experiments [4], which necessitate novel and fast approached for data analysis [5]. Finally, as a very recent development, I will introduce the use of GISAXS in elucidating the nanostructure of flexible electronics [6]. [1] S. V. Roth: “A deep look into the spray coating process in real-time—the crucial role of x-rays”, J. Phys.: Condens. Matter 28, 403003 (2016) [2] M. Schwartzkopf and S. V. Roth: “Investigating Polymer–Metal Interfaces by Grazing Incidence Small-Angle X-Ray Scattering from Gradients to Real-Time Studies”, Nanomaterials 6, 239 (2016) [3] W. Ohm, A. Rothkirch, P. Pandit, V. Körstgens, P. Müller- Buschbaum, R. Rojas, S. Yu, C. J. Brett, D. L. Söderberg, S. V. Roth: “Morphological properties of air-brush spray deposited enzymatic cellulose thin films”, J. Coat. Technol. Res. 15, 759 (2018) [4] M. Schwartzkopf, A. Hinz, O. Polonskyi, T. Strunskus, F. C. Löhrer, V. Körstgens, P. Müller-Buschbaum, F. Faupel, and S. V. Roth: “Role of sputter deposition rate in tailoring nanogranular gold structures on polymer surfaces”, ACS Appl. Mater. Interfaces 9, 5629 (2017) [5] G. Benecke, W. Wagermaier, C. Li, M. Schwartzkopf, G. Flucke, R. Hoerth, I. Zizak, M. Burghammer, E. Metwalli, P. Müller-Buschbaum, M. Trebbin, S. Förster, O. Paris, S. V. Roth, and P. Fratzl: “A customizable software for fast reduction and analysis of large X-ray scattering data sets: applications of the new DPDAK package to small-angle X-ray scattering and grazing-incidence small-angle X-ray scattering”, J. Appl. Cryst. 47, 1797 (2014)Biography Dr. Stephan Volkher Roth is adjunct professor at KTH Royal Institute of Technology in Stockholm, Sweden, and beamline manager of the Micro- and Nanofocus-X-ray scattering beamline P03 including the surface science labs attached at Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany. He studied physics in Bonn, and obtained his PhD at Technische Universität München (TUM), Munich, Germany, in 2001 (Prof. Dr. Petry) in neutron scattering. After his Postdoc at ESRF in Grenoble, France, he moved to DESY, Hamburg in 2004, where he became staff scientist in 2006. His research interests are sustainable biomaterials, nanoparticle formation, hybrid nanostructures, and metal-polymer nanostructures. He focuses on the investigation of coating technology for thin film fabrication using real-time X-ray methods with the aim of correlating the nanostructural evolution in thin films with their optical and electronic functionality. He has an H-index of 38 and authored and co-authored more than 220 peer-reviewed publications. |