A5001823035- Magnetic properties of thin films
- Magnetic Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Microstructure and Mechanical Properties of Steels
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Magneto-Optical Properties and Applications
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- Patient Safety and Medication Errors
- Heusler alloys: electronic and magnetic properties
- nanoparticles nucleation surface interactions
- Phase-change materials and chalcogenides
- Surface and Thin Film Phenomena
- Metallurgical and Alloy Processes
- Rare-earth and actinide compounds
- Child Abuse and Related Trauma
- Ophthalmology and Visual Impairment Studies
- Advanced Antenna and Metasurface Technologies
- Magnetic Properties and Synthesis of Ferrites
- Magnetic Field Sensors Techniques
- Metallic Glasses and Amorphous Alloys
- Corneal surgery and disorders
University of Alabama
2019-2023
Pokhara University
2023
Carnegie Mellon University
2021
Ministry of Health and Population
2019
Department of Health Services
2019
It is well established that the spin-orbit interaction in heavy metal/ferromagnet heterostructures leads to a significant interfacial Dzyaloshinskii-Moriya Interaction (DMI) modifies internal structure of magnetic domain walls (DWs) favor N\'{e}el over Bloch type configurations. However, impact such transition on and stability DW defects (e.g., vertical lines) has not yet been explored. We present combination analytical micromagnetic calculations describe new topological excitation called...
Confirming the origin of Gilbert damping by experiment has remained a challenge for many decades, even simple ferromagnetic metals. Here, we experimentally identify that increases with decreasing electronic scattering in epitaxial thin films pure Fe. This observation conductivitylike damping, which cannot be accounted classical eddy-current loss, is excellent quantitative agreement theoretical predictions due to intraband scattering. Our results resolve long-standing question about...
Two-dimensional van der Waals (vdWs) materials have gathered a lot of attention recently. However, the majority these Curie temperatures that are well below room temperature, making it challenging to incorporate them into device applications. In this work, we synthesized room-temperature vdW magnetic crystal Fe5GeTe2 with temperature T K, and studied its properties by vibrating sample magnetometry (VSM) broadband ferromagnetic resonance (FMR) spectroscopy. The experiments were performed...
Skyrmions hold great promise for low-energy consumption and stable high-density information storage, stabilization of the skyrmion lattice (SkX) phase at or above room temperature is greatly desired practical use. The topological Hall effect can be used to identify candidate systems temperature, a challenging regime direct observation by Lorentz electron microscopy. Atomically ordered FeGe thin films are grown epitaxially on Ge(111) substrates with $\ensuremath{\sim}4%$ tensile strain....
To develop low-moment, low-damping metallic ferromagnets for power-efficient spintronic devices, it is crucial to understand how magnetic relaxation impacted by the addition of nonmagnetic elements. Here, we compare in epitaxial Fe films alloyed with light elements V and Al. FeV alloys exhibit lower intrinsic damping compared pure Fe, reduced nearly a factor 2, whereas FeAl increases Al content. Our experimental computational results indicate that reducing density states at Fermi level,...
We demonstrate the formation of metastable Néel-type skyrmion arrays in Pt/Co/Ni/Ir multi-layers at zero-field following \textit{ex situ} application an in-plane magnetic field using Lorentz transmission electron microscopy. The resultant texture is found to depend on both strength and misorientation applied as well interfacial Dzyaloshinskii-Moriya interaction. To importance angle, we leverage bend contours specimens which coincide with transition regions between labyrinth patterns....
We report on the experimental investigation of perpendicular magnetic anisotropy in $\mathrm{Pt}/{[\mathrm{Co}/\mathrm{Ni}]}_{\mathrm{N}}/\mathrm{Ir}$ multilayers. Broadband ferromagnetic resonance (FMR) and polar angle dependent FMR measurements reveal presence a strong fourth-order contribution to anisotropy. By numerically solving Smit-Beljers relation, we are able fit dependence field extract both second constants. While this model provides qualitative description for all samples, note...
We examine the substructures of magnetic domain walls (DWs) in [Pt/(Co/Ni)M/Ir]N multi-layers using a combination micromagnetic theory and Lorentz transmission electron microscopy. Thermal stability calculations Q=±1 [2π vertical Bloch lines DW skyrmions] were performed geodesic nudged elastic band model, which supports their metastability at room temperature. Experimental variation strength interfacial Dzyaloshinskii–Moriya interaction film thickness reveals conditions under these are...
Spin currents can exert spin-transfer torques on magnetic systems even in the limit of vanishingly small net magnetization, as is case for antiferromagnets. Here, we experimentally show that a torque operative material with weak, short-range order -- namely, macroscopic ensemble superparamagnetic-like Co nanomagnets. We employ element- and time-resolved X-ray ferromagnetic resonance (XFMR) spectroscopy to directly detect sub-ns dynamics nanomagnets, excited into precession cone angle...
Experimental investigations of the perpendicular anisotropy in thin films that are interpreted using a macrospin model often require inclusion higher-order contribution. However, recent ferromagnetic resonance experiments on [Co/Ni]N multilayers indicate cannot explain full angular dependence this system. Using micromagnetic simulations system with lateral variations second-order uniaxial anisotropy, we show while is able to capture average properties along high symmetry orientations by...
Bungee jumping is a recreational sport that involves head-first from certain heights with an elastic cord attached to the person's leg. It has potential develop ocular complications ranging subconjunctival hemorrhage retinal and even detachment.
Abstract Background Binocular vision is a complex process that involves the coordination of two eyes to produce single image. Spectacles and soft contact lenses are common refractive correction options for low myopic astigmatism. However, effect these methods on binocular has not been extensively studied in clinical practice. This study aims investigate acute short-term changes between spectacles spherical equivalent lens wear Purpose To with & Method All subjects underwent thorough...
The discovery of magnetism in two-dimensional (2D) van der Waals (vdW) materials has flourished a new endeavor fundamental problems magnetism. In this talk, we will discuss the magnetization and spin dynamics two types 2D magnets: room-temperature vdW magnetic crystal Fe5GeTe2 with Curie temperature Tc = 332 K Cu(1,3-bdc), quasi-2D magnet Kagome lattice. Ferromagnetic resonance was performed external fields applied along c-axis (H║c) ab-plane (H║ab). We have found sizable Landé g-factor...
Magnetic damping impacts essential dynamics for spintronic device applications, but its fundamental mechanisms in various materials – including simple ferromagnetic metals have yet to be understood. Here, we experimentally correlate with structural and transport properties of epitaxial thin films Fe. At room temperature, the effective Gilbert parameter is independent whether these are coherently strained or partially relaxed. However, at low find that Fe higher crystalline quality...
In this article the influence of a layer dependent second-order perpendicular anisotropy on higher-order anisotropies in thin films framework macrospin model is investigated. Second-order and fourth-order effective are necessary to achieve reasonable description micromagnetic results using approximation. We found that origin linked layer-wise variation magnetization direction structure leading dependence field strength exchange stiffness. Our show apparent increases with decrease stiffness...