A5030878724- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Magnetic Properties of Alloys
- Advanced Electron Microscopy Techniques and Applications
- Metallic Glasses and Amorphous Alloys
- Quantum and electron transport phenomena
- Magnetic Properties and Applications
- ZnO doping and properties
- Multiferroics and related materials
- Advanced Thermoelectric Materials and Devices
- Characterization and Applications of Magnetic Nanoparticles
- Advanced X-ray Imaging Techniques
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Topological Materials and Phenomena
- Architecture and Computational Design
- Augmented Reality Applications
- Chalcogenide Semiconductor Thin Films
- Theoretical and Computational Physics
- Advanced Materials Characterization Techniques
- Iron oxide chemistry and applications
- Magnetic Field Sensors Techniques
- Crystal Structures and Properties
- Surface Roughness and Optical Measurements
University of Wisconsin–Madison
2015-2022
Oregon State University
2016
University of Oregon
2012-2014
High-quality metal halide perovskite single crystals have low defect densities and excellent photophysical properties, yet thin films are the most sought after material geometry for optoelectronic devices. Perovskite single-crystal (SCTFs) would be highly desirable high-performance devices, but their growth remains challenging, particularly inorganic perovskites. Herein, we report facile vapor-phase epitaxial of cesium lead bromide (CsPbBr3) continuous SCTFs with controllable micrometer...
Skyrmions, novel topologically stable spin vortices, hold promise for next-generation magnetic storage due to their nanoscale domains enable high information density and low threshold current-driven motion ultralow energy consumption. One-dimensional (1D) nanowires are ideal hosts skyrmions since they not only serve as a natural platform racetrack memory devices but also can potentially stabilize skyrmions. Here we use the topological Hall effect (THE) study phase stability dynamics of in...
Abstract Magnetic skyrmions are topologically stable whirlpool-like spin textures that offer great promise as information carriers for future spintronic devices. To enable such applications, particular attention has been focused on the properties of in highly confined geometries one-dimensional nanowires. Hitherto, it is still experimentally unclear what happens when width nanowire comparable to a single skyrmion. Here, we achieve this by measuring magnetoresistance ultra-narrow MnSi We...
Cobalt phosphosulfide (CoPS) has recently emerged as a promising earth-abundant electrocatalyst for the hydrogen evolution reaction (HER). Nonetheless, influence of crystallographic surface on HER activity CoPS and other nonmetallic electrocatalysts remains an important open question in design high-performance catalysts. Herein, activities (100) (111) facets single crystals were studied using complementary experimental computational approaches. Natural polished selectively exposed to reveal...
Abstract Silicon is an extremely important technological material, but its current industrial production by the carbothermic reduction of SiO 2 energy intensive and generates CO emissions. Herein, we developed a more sustainable method to produce silicon nanowires (Si NWs) in bulk quantities through direct electrochemical CaSiO 3 , abundant inexpensive Si source soluble molten salts, at low temperature 650 °C using low‐melting‐point ternary salts CaCl –MgCl –NaCl, which still retains high...
Using dynamic cantilever magnetometry we measure an enhanced skyrmion lattice phase extending from around 29 K down to at least 0.4 in single MnSi nanowires (NWs). Although recent experiments on two-dimensional thin films show that reduced dimensionality stabilizes the phase, our results are surprising given NW dimensions much larger than constant. Furthermore, stability of depends orientation NWs with respect applied magnetic field, suggesting effective anisotropy, likely due large...
Abstract Magnetic skyrmions are stable nanosized spin structures that can be displaced at low electrical current densities. Because of these properties, they have been proposed as building blocks future electronic devices with unprecedentedly high information density and energy consumption. The detection an ordered skyrmion lattice via the Topological Hall Effect (THE) in a bulk crystal, has so far demonstrated only cryogenic temperatures MnSi family compounds. Here, we report observation...
Envisaged applications of Skyrmions in magnetic memory and logic devices crucially depend on the stability mobility these topologically nontrivial textures thin films. We present for first time quantitative maps induction that provide evidence a 3D modulation Skyrmionic spin texture. The projected in-plane as determined from in-line off-axis electron holography carry clear signature Bloch Skyrmions. However, magnitude this is much smaller than values expected homogeneous extend throughout...
Iron monogermanide (FeGe) with the noncentrosymmetric cubic B20 structure is a well-known helimagnet and magnetic skyrmion host relatively high ordering temperature (∼280 K). FeGe related metal compounds, such as CoGe MnGe, have several structural polymorphs typically require pressure (∼4 GPa) (∼1000 °C) to synthesize in structure. Here, we report that phase of both alloys Fe1–xCoxGe could fact be formed without application by simply reacting elemental powders at modest temperatures (550...
Magnetic skyrmions are a new form of magnetic ordering with whirlpool-like spin arrangements. These topologically protected particlelike textures were first discovered decade ago in noncentrosymmetric materials. Confining nanostructures leads to interesting fundamental insights into skyrmion stability and could provide convenient platforms for potential practical applications information storage technology. In this research update, we summarize the recent advances on studying hosting...
Abstract Magnetic skyrmions are topologically protected spin textures that being investigated for their potential use in next generation magnetic storage devices. Here, and other phases Fe 1− x Co Ge ( < 0.1) microplates (MPLs) newly synthesized via chemical vapor deposition studied using both imaging transport measurements. Lorentz transmission electron microscopy reveals a stabilized skyrmion phase near room temperature (≈280 K) quenched metastable lattice field cooling....
Abstract In bulk chiral crystals, 3D structures of magnetic skyrmions form topologically protected skyrmion strings (SkS) that have shown potential as magnonic nano‐waveguides for information transfer. Although SkS stability is expected to be enhanced in nanostructures skyrmion‐hosting materials, experimental observation and detection under an applied in‐plane field difficult. Here, temperature‐dependent field‐driven creation annihilation B20 FeGe (nanowires nanoplates) ( H || ) are the...
Magnetic skyrmions are topological spin textures that have shown promise for future nonvolatile memory devices. Herein, we report on the stability of magnetic in alloyed cubic B20 Fe1–xCoxSi nanowires (NWs) determined using off-axis electron holography and magnetotransport measurements. This study presents real space observation one-dimensional skyrmion lattice a NW which shows phase Fe0.75Co0.25Si exists at lower applied fields (200 Oe) with reduced domain size (28 ± 2 nm) comparison to...
The study of nanoscale chiral magnetic order in polycrystalline materials with a strong Dzyaloshinskii-Moriya interaction is interesting for the observation phenomena at grain boundaries and interfaces. This especially true materials, which can be grown using scalable techniques, scalability promising future device applications. One such material sputter-deposited B20 $\mathrm{Fe}\mathrm{Ge}$ on $\mathrm{Si}$, actively investigated as basis low-power high-density memory technology platform....
The synthesis and characterization of a new layered compound with the composition (PbSe) 1·16 TiSe 2 in thin-film form is reported this study. structure was characterized by specular in-plane synchrotron x-ray diffraction studies, which indicate that can be described as intergrowth PbSe individual constituents are precisely yet rotationally (turbostratically) disordered an average domain size order 10 nm. In contrast to crystalline (TiSe ) prepared solid-state reaction at high temperature,...
Layered metal dichalcogenide materials (MX2) have great potential for solar energy conversion. However, as-grown MX2 often contain edge and terrace defects that degrade semiconducting properties hinder their performance. Herein, we demonstrate a simple approach to removing surface improving the performance by using UV-generated ozone oxidize of WSe2 nanoplates single crystals, followed soak in aqueous solutions remove oxide. Structural characterizations reveal defective edges basal plane...
Understanding spin-wave dynamics in chiral magnets is a key step for the development of high-speed, based spintronic devices that take advantage and topological spin textures their operation. Here, we present an experimental theoretical study cubic B20 FeGe single crystal. Using combination waveguide microwave absorption spectroscopy (MAS), micromagnetic simulations, analytical theory, identify resonance all magnetic phases (field polarized, conical, helical, skyrmion phases). Because...
Abstract A new metastable compound Cr 3 Sb was synthesized as thin film starting from modulated elemental reactant layers. The is cubic and crystallizes in the A15 structure (Cr Si-type). variation of occupancy position (0, 0, 0) observed leading to a Cr-rich sample with formula ∼6 Sb. In-situ X-ray diffraction reflectivity investigations indicate an interdiffusion multilayers crystallization below 350°C. Calculations crystal lattice parameter agree well experimental results. In addition...
Structural disorder can play an important role in the electrical properties of correlated materials. In this work we examine average and local hollandites AxRu4O8 (A+ = K, Rb, Rb1–xNax) through neutron total scattering techniques. Samples with A+ Rb1–xNax exhibit largest amount as evidenced by higher atomic displacement parameters, a result, weakened temperature dependence resistivity is observed upon cooling compared to KxRu4O8. All samples anisotropic that dominated metallic conductivity...