Robert Streubel and co‐workers report the formation of topological magnetization vector fields in disordered materials with local inversion symmetry breaking, harnessing high‐resolution Lorentz microscopy, quantitative x‐ray microspectroscopy, and coherent scattering. The image shows the reconstructed in‐plane magnetic induction of closely packed Bloch skyrmions embedded into helical spins. Read more »
ALS Work Using XMCD
From Stripes to Skyrmions in a Surprising Material
Researchers showed that tiny bubbles of ordered spins (skyrmions) can be induced to form in a material previously considered incompatible with skyrmion formation. The discovery opens up a new class of material systems that exhibit technologically desirable nanoscale features attractive for spintronic applications. Read more »
Controlling Magnetization Vector Depth Profiles of La0.7Sr0.3CoO3/La0.7Sr0.3MnO3 Exchange Spring Bilayers via Interface Reconstruction
Polarized neutron reflectometry was combined with soft x-ray magnetic spectroscopy to quantify the changes in the magnetic and chemical depth profiles in La0.7Sr0.3CoO3/La0.7Sr0.3MnO3 bilayers, confirming the formation of interfacial layers with distinct magnetization and chemical density. Read more »
Antiferromagnet Transmits Coherent Spin Waves
Researchers discovered how pure spin currents (also known as spin waves) can be efficiently and coherently transmitted through an electrically insulating antiferromagnetic material. The work represents a notable milestone in the use of antiferromagnetic materials for low-power spintronic devices at room temperature. Read more »
Tunable Ferromagnetism in a 2D Material at Room Temperature
Researchers combined soft x-ray spectroscopy and microscopy to demonstrate the tunable ferromagnetic characteristics of a two-dimensional layered material at room temperature. The results open up exciting opportunities for the use of such materials in low-power spintronics, high-density magnetic storage, and flexible electronics. Read more »
Ordered Magnetic Patterns in a Disordered Magnetic Material
Scientists have confirmed the presence of chirality, or handedness, in nanometers-thick samples of amorphous (noncrystalline) multilayer materials. The chirality—which potentially could be exploited to transmit and store data in a new way—was observed in the domain walls between neighboring regions of opposite spin. Read more »
Experimental Evidence of Chiral Ferrimagnetism in Amorphous GdCo Films
Harnessing high‐resolution Lorentz microscopy, Robert Streubel and co‐workers visualize chiral ferrimagnetic domain walls in amorphous films, revealing a composition dependence that potentially enables a temperature control of intrinsic domain wall properties. The reconstructed electron phase (magnetic induction) of achiral Bloch domain walls is shown here. Read more »
Reversible Fe(II) uptake/release by magnetite nanoparticles
The coexistence of magnetite and aqueous Fe2+ is common in anoxic subsurface environments and can have a great influence on important biogeochemical redox processes. This study demonstrates that the flow direction of electron equivalents in the form of Fe(II) across the magnetite–solution interface changes in a predictable fashion by altering solution pH, background Fe2+(aq) concentration, and magnetite loading. Read more »
Non-Crystal Clarity: Scientists Find Ordered Magnetic Patterns in Disordered Magnetic Material
Scientists have confirmed the presence chirality, or handedness, in nanometers-thick samples of amorphous (noncrystalline) multilayer materials. The chirality—which potentially could be exploited to transmit and store data in a new way—was observed in the domain walls between neighboring regions of opposite spin. Read more »
Imaging Magnetic Microstructure Response to Substrate Strain
A ferromagnetic thin film on a piezoelectric substrate offers a way to control magnetization in ultralow-power devices by relying on coupling between the piezoelectric and ferromagnetic components. At the ALS, researchers were able to image the electrically induced magnetic behavior and correlate it with the piezo-strain driving it. Read more »
