A5106072979- Magnetic properties of thin films
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Advanced Materials Characterization Techniques
- Magnetic Properties and Applications
- nanoparticles nucleation surface interactions
- Semiconductor materials and interfaces
- Metallic Glasses and Amorphous Alloys
- Surface and Thin Film Phenomena
- Titanium Alloys Microstructure and Properties
- Microstructure and mechanical properties
- Magnetic Properties of Alloys
- Additive Manufacturing Materials and Processes
- Intermetallics and Advanced Alloy Properties
- Magnesium Alloys: Properties and Applications
- Theoretical and Computational Physics
- Catalytic Processes in Materials Science
- Magnetic Properties and Synthesis of Ferrites
- Semiconductor materials and devices
- High Entropy Alloys Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Aluminum Alloy Microstructure Properties
- Advanced materials and composites
- Aluminum Alloys Composites Properties
- Hydrogen embrittlement and corrosion behaviors in metals
Osaka University
2016-2025
Tohoku University
2011-2024
National Institute of Technology, Ichinoseki College
2007-2023
University of Toyama
2023
Binghamton University
2016
Institute for Materials Research, Tohoku University
2009-2016
IMEC
2016
KU Leuven
2016
National Institute of Advanced Industrial Science and Technology
2016
Kyushu Institute of Technology
2016
Fully epitaxial Co2FexMn1−xSi(CFMS)/Ag/Co2FexMn1−xSi current-perpendicular-to-plane giant magnetoresistive devices with various Fe/Mn ratios x and top CFMS layer thicknesses tCFMS were prepared. The highest magnetoresistance (MR) ratios, 58% at room temperature 184% 30 K, observed in the sample = 0.4 3 nm. Enhancement of interface spin-asymmetry was suggested for compared that 0. A MR ratio also even a very thin trilayer structure, CFMS(4 nm)/Ag(3 nm)/CFMS(2 nm), which is promising...
Chemically ordered hard magnetic L10-FeNi phase of higher grade than cosmic meteorites is produced artificially. Present alloy design shortens the formation time from hundreds millions years for natural to less 300 hours. Electron diffraction detects four-fold 110 superlattice reflections and a high chemical order parameter (S 0.8) developed phase. The field more 3.5 kOe required switching magnetization. Experimental results along with computer simulation suggest that formed due three...
Element segregation and consequent phase separation are challenging problems in refractory high entropy alloys (RHEAs). In this study, thermodynamic parameters calculation of diagrams (CALPHAD) were implemented for RHEA design to suppress separation. A novel non-equiatomic RHEA, Ti1(NbMoTa)2W0.5 alloy, was designed with a minimized difference between liquidus solidus temperatures (ΔTl−s) wide temperature range transformation (ΔTsingle) compared equiatomic RHEA. As-cast alloy maintained...
The atomic structure of CoPt and FePt nanoparticles (with a diameter between 2 5 nm) has been studied by transmission electron microscopy. particles have produced laser vaporization cluster source annealed under vacuum in order to promote chemical ordering. For both alloys, we observe coexistence crystalline multiply twinned with decahedral or icosahedral shapes. In addition corresponding single $L{1}_{0}$ ordered domain, put into evidence that even small can display several domains....
This paper proposes a novel control method based on the virtual AC/DC/AC conversion for matrix converter. The is very simple strategy to input current and output voltage There are two new topics proposed in this paper. Firstly, minimum switching loss modulation rectifier. In case of modulation, only arms rectifier using dc link by inverter can obtain clean sinusoidal current. Secondly, lean controlled carrier proposed. leans triangle duty ratio side pulse. reduces harmonic distortion...
The Ni nanoparticles with fcc or hcp phases have been synthesized in tetraethylene glycol by using the modified polyol process. crystal structure has controlled changing polyol/Ni mole ratio and reaction temperature. saturation magnetization of as-prepared particles depends on relative volume fraction phase. x-ray diffraction extended absorption fine studies suggest formation pure phases. show nonmagnetic behavior thermally stable below 673K.
Microcrystals of coesite and stishovite were discovered as inclusions in amorphous silica grains shocked melt pockets a lunar meteorite Asuka-881757 by micro-Raman spectrometry, scanning electron microscopy, back-scatter diffraction, transmission microscopy. These high-pressure polymorphs SiO 2 indicate that the experienced an equilibrium shock-pressure at least 8–30 GPa. Secondary quartz are also observed separate meteorite. The estimated age reported 39 Ar/ 40 Ar chronology indicates...
Thin films of oriented tetragonal FePt particles separated by amorphous alumina have been fabricated electron beam evaporation. The ordering the without coarsening can be tailored annealing conditions. value coercivity annealed film reached as high 4.4 kOe. perpendicular magnetic was slightly larger than in-plane coercivity. Some were found to {111} twins and stacking faults. From our high-resolution microscopy observations, it determined that central region ordered tended c-axis plane.
Thin films of oriented island-like crystallites L10 FePt separated by amorphous (a-)Al2O3 were fabricated. The process took advantage the overgrowth α-Fe on Pt “seed” particles epitaxially grown (100) NaCl and MgO substrates ordering reaction between Fe upon annealing at temperatures higher than 500 °C. coercivities annealed (600 °C for 6 h) a-Al2O3/Fe(1 nm)/Pt (1.5 nm) both are 3.3 kOe. Transmission electron microscopy observation showed that film consisted crystals with an average size 12...
In sharp contrast to previous studies on FeRh bulk, thin films, and nanoparticles, we report the persistence of ferromagnetic order down 3 K for size-selected 3.3 nm diameter nanocrystals embedded into an amorphous carbon matrix. The annealed nanoparticles have a B2 structure with alternating atomic Fe Rh layers. X-ray magnetic dichroism superconducting quantum interference device measurements demonstrate alignment moments 1μ(B), respectively. is ascribed finite-size induced structural...
This study investigated modulation of the long period stacking order (LPSO) structure in aged Mg97Zn1Y2 alloys using conventional transmission electron microscopy (TEM) and aberration-corrected high-angle annular dark field-scanning (HAADF-STEM). The irregular sequence a fragment 24R-type LPSO acts as catalyst for transformation from 18R- to 14H-type LPSO. elementary step takes place by ledge-pair movement on different (0001)Mg planes with Shockley partial dislocations. Each ledge has...
Isolated 10-nm-sized FePd nanoparticles with the L10-type ordered structure have been fabricated by electron-beam evaporation and postannealing above 773 K, structural details investigated transmission electron microscopy. particles were epitaxially grown on a cleaved NaCl(001) substrate two-dimensionally dispersed substrate. In formation, Pd first deposited as “seed” NaCl followed successive deposition of Fe particles. All captured forming Fe/Pd nanocomplex mutual fixed orientation....