A5082440573- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Advanced Memory and Neural Computing
- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Quantum and electron transport phenomena
- Magneto-Optical Properties and Applications
- Characterization and Applications of Magnetic Nanoparticles
- Magnetic Properties and Applications
- Ferroelectric and Negative Capacitance Devices
- Semiconductor materials and devices
- ZnO doping and properties
- Advanced Condensed Matter Physics
- Copper Interconnects and Reliability
- Neural Networks and Reservoir Computing
- Ferroelectric and Piezoelectric Materials
- Advanced Fiber Laser Technologies
- Magnetic confinement fusion research
- Particle Accelerators and Free-Electron Lasers
- Copper-based nanomaterials and applications
- Advanced Electron Microscopy Techniques and Applications
- Shape Memory Alloy Transformations
- Nonlinear Dynamics and Pattern Formation
- Advanced Semiconductor Detectors and Materials
- Nanoporous metals and alloys
Hangzhou Dianzi University
2015-2024
Argonne National Laboratory
2012-2021
Fudan University
2014-2019
State Key Laboratory of Surface Physics
2014-2019
Collaborative Innovation Center of Advanced Microstructures
2015-2016
Science and Technology on Surface Physics and Chemistry Laboratory
2014
Kyung Hee University
2014
IBM (United States)
2002
University of Minnesota
1996
Abstract Deterministic switching of perpendicularly magnetized synthetic antiferromagnets using spin‐orbit torque (SOT) usually requires an in‐plane auxiliary magnetic field, which limits its practical applications. Here, exchange field gradient is introduced into ferro‐ and (SFs SAFs) through the insertion a slightly wedged Ru between two thin ferromagnetic layers, induces field‐free perpendicular SFs SAFs with ratio up to 81% regardless nature coupling. Temperature‐dependent measurement...
Abstract Controlling the multi‐state switching is significantly essential for extensive utilization of 2D ferromagnet in magnetic racetrack memories, topological devices, and neuromorphic computing devices. The development all‐electric functional nanodevices with a rapid reset remains challenging. Herein, to imitate potentiation depression process biological synapses, full‐current strategy unprecedently established by controllable resistance‐state originating from spin configuration...
The front end of any modern ion accelerator includes a radio frequency quadrupole (RFQ). While many pulsed linacs successfully operate RFQs, several accelerators worldwide have significant difficulties operating continuous wave (CW) RFQs to design specifications. In this paper we describe the development and results beam commissioning CW RFQ designed built for National User Facility: Argonne Tandem Linac Accelerator System (ATLAS). Several innovative ideas were implemented in RFQ. By...
Step-induced antiferromagnetic (AFM) uniaxial anisotropy and its effects on the exchange coupling have been systematically investigated in epitaxial $\mathrm{Fe}/\mathrm{CoO}$ bilayers a $\mathrm{MgO}(001)$ vicinal surface. X-ray magnetic linear dichroism measurements proved that atomic steps induced strong in-plane AFM CoO film. We found thermal activation 90\ifmmode^\circ\else\textdegree\fi{} switching of spins. The competition among step-induced anisotropy, interface coupling, generate...
The anisotropic magnetoresistance (AMR) in epitaxial $\mathrm{Pt}/\mathrm{Fe}/\mathrm{MgO}(001)$ bilayers was systematically studied as a function of Pt thickness, and strong enhancement AMR by the $\mathrm{Pt}$ layer observed. persists with 1 nm Au inserted between Fe but disappears $\mathrm{MgO}$ layer. Both spin Hall theory induced moments located at $\mathrm{Fe}/\mathrm{Pt}$ interface cannot explain observed enhancement. enhanced $\mathrm{Pt}/\mathrm{Fe}$ bilayer can be attributed to...
Abstract Magnetic proximity effect between two magnetic layers is an important focus of research for discovering new physical properties systems. Antiferromagnets (AFMs) are fundamental systems with ordering and promising candidate materials in the emerging field antiferromagnetic spintronics. However, bilayers rarely studied because detecting spin orientation AFMs challenging. Using X-ray linear dichroism magneto-optical Kerr measurements, we investigated effects epitaxial CoO/NiO/MgO(001)...
Voltage-controlled spintronic devices utilizing the spin degree of freedom are desirable for future applications, and may allow energy-efficient information processing. Pure current can be created by thermal excitations in magnetic systems via Seebeck effect (SSE). However, controlling such currents, only electrical means, has been a fundamental challenge. Here, we investigate voltage control SSE antiferromagnetic insulator Cr2O3. We demonstrate that response generated this material...
The magnetic properties of antiferromagnetic (AFM) spins were investigated using x-ray linear dichroism (XMLD) in epitaxial NiO/CoO/MgO(001) films as a function film thickness, temperature, and interface modulation. We found that the NiO AFM undergo spin reorientation transition (SRT) from in-plane orientation to out-of-plane at critical thickness. SRT can be attributed competition between anisotropy interfacial exchange coupling with CoO spins. thickness increases also strength....
The effect of the Dzyaloshinskii–Moriya (DM) interaction on vortex in magnetic microdisk was investigated by micro-magnetic simulation based Landau–Lifshitz–Gilbert equation. Our results show that DM modifies size core, and also induces an out-of-plane magnetization component at edge inside disk. can destabilizes one handedness, generate a bias field to core couple polarity chirality. This DM-interaction-induced coupling therefore provide new way control
Determining the magnetic structure of antiferromagnets is a fundamental challenge for basic understanding and development antiferromagnetic spintronic devices. However, apart from techniques that probe individual spins in directly (such as spin-polarized scanning tunneling microscopy), there are few can provide independent information each sublattice. Here, authors demonstrate spin Seebeck signals insulator Cr${}_{2}$O${}_{3}$ controlled by surface spins, independently detect orientation two...
The effect of the Dzyaloshinskii–Moriya interaction (DMI) on magnetic vortex gyration is investigated systematically through micromagnetic simulations. Our results show that DMI can lift degeneracy eigenfrequencies for vortices with left- and right-handedness. For excited by an in-plane AC resonant field, strongly influence amplitude critical field core switching, depending sign handedness. DMI-induced edge state has a strong as approaches disk edge.
Spin-flip probabilities from bulk defects and phonons are determined for the mesoscopic Cu channels of nonlocal spin valves (NLSVs). The NLSV signals analyzed by a new approach to consistently extract in situ values diffusion length, effective injection (detection) polarization, resistivity. size variations injectors (detectors) between NLSVs treated normalizing be commensurate with standard injector (detector) size. microstructure statistically accounted measuring many on same substrate....
The interactions between electric and magnetic subsystems in a ferroelectric-ferromagnetic composite occur through mechanical forces. Here we discuss results of systematic investigation on the strength response to an applied field, known as converse magnetoelectric (CME) effect, its dependence ferroic order parameters volume fraction for two phases. Studies were carried out composites lead zirconate titanate 2--30-\ensuremath{\mu}m-thick nickel zinc ferrite (NZFO) films grown by liquid phase...
Electric current sensors are widely utilized in high-frequency power and electronic circuits which spread over numerous industries. Here, a sensor based on the high-Q whispering gallery mode optical capillary microresonator filled with Terfenol-D nanoparticles is experimentally demonstrated. The device shows peak AC sensitivity of 5.285 μA Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1/2</sup> corresponding high accuracy 0.0009%. It...
The electrical control of vortex polarity and chirality is in high demand for spintronic oscillators, memory, computing. Previous studies have shown that can be efficiently switched by current, while not. Here the authors report dynamic transformation edge solitons able to switch both $a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}d$...
The recent discovery of bulk spin–orbit torques (SOTs) in magnetic single layers has attracted much attention. However, currently, it remains elusive as to how understand and tune such SOTs. In this study, we study the tunability SOTs CoPt films, by annealing temperature. Our results show that field-free switching can be realized after optimized at 450 °C. performance is consistent with out-of-plane SOT efficiency, which also appears maximized crystal-axis dependence reveals besides...
Spin–orbit torque (SOT) is an emerging candidate for electrically controlled magnetization switching in low-power and nonvolatile spintronic devices. However, SOT of perpendicular requires auxiliary field or additional lateral symmetry breaking, which difficult to achieve practical applications. In particular, the mechanism field-free through vertical breaking still lacks a quantitative description. this work, vertically asymmetric Co/Pt bilayer has been constructed engineering anisotropy...
Strain-induced modulation of perpendicular magnetic anisotropy (PMA) is demonstrated in a wedge-shaped Pt/Co/Pt sandwich grown on PMN-PT(0 1 1) substrate using torque measurements. An anisotropic in-plane strain generated by applying an electric field across the PMN-PT and transferred to ferromagnetic sandwich. The critical thickness spin reorientation transition tuned thicker region wedge. strain-induced change PMA quantitatively extracted. Only first order term field, while second has...
We fabricate a large number $(>100)$ of nonlocal spin valves with mesoscopic Cu channels. A systematic method is used to extract resistivity ${\ensuremath{\rho}}_{\mathrm{Cu}}$ and relaxation length ${\ensuremath{\lambda}}_{\mathrm{Cu}}$ from each given structure. relationship between established over broad range (from 0.7 $>10\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{\ensuremath{\Omega}}\phantom{\rule{4pt}{0ex}}\mathrm{cm}$) $>200$ data points obtained at 10 295 K. Quantitative...
Advanced write head designs improve efficiency by reducing yoke length to less than 15 /spl mu/m, adapting a sunken coil/P1 pedestal structure with stitched pole, and utilizing high moment poles greater 2 T moment. Sufficient bit-error rate was achieved up 680 kBPI using heads 50-60 GB/in/sup 2/ dimensions. For wider track width heads, spin-stand testing showed good writing parametrics soft error 1.0-1.1 Gb/s channel data rate, product electronics channels. The feasibility of high-speed...
The current-induced magnetization switching and damping-like field in Pt/(Co/Pt)/PtMn trilayer films prepared with without an situ in-plane of 600 Oe have been studied systematically. In the presence field, a small bias (HEB) is observed for PtMn thickness ≥5 nm, while there no observable HEB ≤3 nm. Nevertheless, field-free perpendicular Co/Pt all 1-7 On other hand, are not seen. Furthermore, fields (HDL) much enhanced increasement can be up to 47%. We further revealed that spin current...
This spin-stand measurement study focuses on recording characteristics at submicron scale track width. The pole tips of a set identical thin film heads were trimmed from the air-bearing surface by focused ion beam etching. A with widths ranging W=2 μm to W=0.5 produced. Recording experiments performed high precision tester using these heads. Both on-track and off-track performances studied analyzed. As width is scaled down, degrading performance observed. When head decreased, onset partial...