A5011051037- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Magnetic Properties and Applications
- Heusler alloys: electronic and magnetic properties
- Magnetic Properties and Synthesis of Ferrites
- Magnetic Properties of Alloys
- Thermal Expansion and Ionic Conductivity
- Magneto-Optical Properties and Applications
- Advanced Condensed Matter Physics
- ZnO doping and properties
- Tribology and Lubrication Engineering
- Theoretical and Computational Physics
- Characterization and Applications of Magnetic Nanoparticles
- Pigment Synthesis and Properties
- Thermal properties of materials
University of Alabama
2008-2022
National Institute for Materials Science
2015-2019
University of Tsukuba
2015
Although single-crystalline spinel (MgAl2O4)-based magnetic tunnel junctions (MTJs) are known to show a good bias voltage dependence of magnetoresistance (TMR) ratio over MgO-based MTJs, no polycrystalline MgAl2O4-based MTJs exhibiting large TMR ratios have been grown previously due the lack crystallinity MgAl2O4 barrier. In this work, we demonstrate growth polycrystalline-based with exceeding 240% and an improved compared that MTJs. An ultra-thin CoFe/MgO seed layer on amorphous CoFeB...
Samarium (Sm) doped M-type strontium ferrite single crystals have been successfully grown from melts using a flux system of SrCO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and Na xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> CO . The exhibited the typical hexagonal growth habit with plate-like geometry, largest obtained are 10 mm in length 3-4 thickness, respectively. It was observed that saturation magnetization anisotropy...
Liquid phase epitaxy technique was used to grow 144 μm thick barium ferrite (BaFe12O19; BaM) single crystalline films on (111) Gd3Ga5O12 substrate. The growth rate of 72 μm/h achieved with a flux system Fe2O3–BaCO3–Na2CO3. grown BaM show (000l) orientation that confirmed by x-ray diffraction and magnetic torque curves. saturation magnetization (4πMs) the anisotropy field (Hk) were found be 4.2 kG 16.0 kOe, respectively. ferrimagnetic resonance linewidth (ΔH) at 35 GHz measured 0.1 kOe.
Perpendicularly magnetized flat thin films of antiperovskite Mn67Ga24N9 were grown on an MgO(001) substrate by reactive sputtering using argon/1% nitrogen gas mixture and a Mn70Ga30 target. The showed saturation magnetization 80 –100 kA/m, effective perpendicular magnetic anisotropy (PMA) energy 0.1–0.2 MJ/m3, Curie temperature 660–740 K. Upon increasing the N composition, transformed from ferromagnetic to antiferromagnetic as expected in stoichiometric Mn3GaN phase. Point contact Andreev...
Electrical manipulation of magnetization by spin-orbit torque (SOT) has shown promise for realizing reliable magnetic memories and oscillators. To date, the generation transverse spin current SOT, whether it is Hall effect (SHE), Rashba-Edelstein or spin-momentum locking origin, relies primarily on materials heterostructures containing 5$d$ 6$p$ heavy elements with strong coupling. Here we show that a paramagnetic CoGa compound possesses large enough angle to allow robust SOT switching...
We study the relationship between long range order parameters and magnetocrystalline anisotropy of off-stoichiometric D022 Mn2.36Ga (MnGa) epitaxial films grown on MgO (001) SrTiO3 (STO) single crystalline substrates. MnGa deposited show rather large irregular variation in magnetization with increasing substrate temperature spite improved total atomic sites. The specific site Mn-I characterized [101] orientation revealed fluctuation occupation fraction two Mn sites elevated temperature,...
We report the tunable magnetic properties and smoothened surface morphology of epitaxial D022 Mn-Ga (Mn3Ga Mn2.5Ga) films by N doping using reactive sputtering at 480 °C. The 50 nm thick grown with N2/Ar gas flow rate (η) up to 0.66% showed 33%–50% reduction in saturation magnetization compared non-doped Mn-Ga. In particular, a single phase was obtained an optimal η range for Mn2.5Ga, resulted perpendicular anisotropy energy density ∼1 MJ/m3 33% magnetization. Furthermore, introduction...
We report the growth of (001)-textured polycrystalline D022 MnGa films with perpendicular magnetic anisotropy (PMA) on thermally oxidized Si substrates using an (Mg0.2Ti0.8)O (MTO) buffer layer. The ordered film grown at optimum substrate temperature 530 °C MTO layer shows PMA magnetization 80 kA/m, energy density 0.28 MJ/m3, and coercivity 2.3 T. scanning transmission electron microscope analysis confirms formation a highly structure elementally sharp interfaces between achieved amorphous...
We report on the tunnel magnetoresistance (TMR) effect of perpendicular magnetic junctions (p-MTJs) composed a ferromagnetic antiperovskite MnGaN film with anisotropy. The p-MTJ multilayer stack MnGaN/Mg/MgO/Fe/CoFeB was used to control MgO interface conditions by Mg and Fe insertion layers. under barrier enhanced anisotropy top Fe/CoFeB layers post-annealing process, thus nearly perfect magnetization realized. A TMR ratio up 3.7%$\sim 3.8$ % obtained at room temperature. low is mainly...
Polarized and unpolarized neutron diffraction techniques have been applied to study the temperature-dependent magnetic structural properties of four 200 nm-thick Fe 50 Pt 50− x Rh films with = 5, 10, 17.5 25. Similar bulk system, an antiferromagnetic ferromagnetic transition can be found in decreasing concentration. The application structure factor calculations enables one determine microscopic configuration different as a function temperature developed models indicate from dominant order...
The properties of Fe–Rh–Pd epitaxial thin films grown on MgO(001) were studied as a function growth temperature. Films above 400°C exhibit first-order antiferromagnetic to ferromagnetic magnetic phase transition with temperature that decreases the is increased. chemical order parameter computed from ratio intensities (001) and (002) diffraction peaks nearly independent temperature, while lattice constants change slightly. A comparison our structural, magnetic, electrical transport results...