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 »
ALS Work Using XMCD
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 »
Tuning Magnetic Frustration in a Dipolar Trident Lattice
Researchers designed and fabricated a nanomagnet array in which competing (“frustrated”) magnetic interactions can be directly tuned. Frustrated interactions are key to a wide range of phenomena, from protein folding and magnetic memory to fundamental studies of emergent exotic states. Read more »
X-Rays Reveal ‘Handedness’ in Swirling Electric Vortices
Scientists used spiraling x-rays at the ALS to observe, for the first time, a property that gives handedness to swirling electric patterns—dubbed polar vortices—in a synthetically layered material. Read more »
Ferromagnetism Emerges to Alleviate Polar Mismatch
A polar mismatch between nonferromagnetic materials drives an electronic reconstruction in which interfacial ferromagnetism is induced. The emergence of such functionality at interfaces could enable new types of electronics for a range of applications, including logic, memory, sensing, and more. Read more »
A New Way to Tune Emergent Magnetism
Perpendicular magnetic anisotropy (PMA)—where magnetic moments in a thin film preferentially point out of the plane of the film—is an emergent phenomenon of both fundamental and technological interest. A combination of x-ray techniques demonstrate how to tune PMA in transition-metal oxide multilayers. Read more »
