A5074994329- Magnetic Properties of Alloys
- Magnetic Properties and Applications
- Magnetic properties of thin films
- Metallic Glasses and Amorphous Alloys
- Magnetic Properties and Synthesis of Ferrites
- Hydrogen Storage and Materials
- Rare-earth and actinide compounds
- Microstructure and Mechanical Properties of Steels
- Superconducting Materials and Applications
- Metallurgical and Alloy Processes
- Magnetic and transport properties of perovskites and related materials
- Iron oxide chemistry and applications
- Cellular and Composite Structures
- Electromagnetic wave absorption materials
- Electric Motor Design and Analysis
- Heusler alloys: electronic and magnetic properties
- Physics of Superconductivity and Magnetism
- Magneto-Optical Properties and Applications
- Polymer Foaming and Composites
- Semiconductor Quantum Structures and Devices
- Optimal Power Flow Distribution
- Microstructure and mechanical properties
- Aluminum Alloy Microstructure Properties
- Induction Heating and Inverter Technology
- Metallurgy and Material Forming
University of Fukui
2020-2022
Research Institute for Electromagnetic Materials
2014-2019
TEPCO (Japan)
2015-2018
Yokohama National University
2006-2015
Kyoto University
2011-2014
Kanagawa University
2014
Hosei University
2012-2014
Tokyo University of Agriculture and Technology
2011
Tokyo University of Technology
2009-2010
Waseda University
1977-2010
The electromagnetic wave absorption properties of Ba M-type (BaFe/sub 12-x/(Ti/sub 0.5/Mn/sub 0.5/)/sub x/O/sub 19/) ferrite-epoxy resin composites were investigated. After measuring the complex permittivities samples, regions permeabilities in which reflection loss (R.L.) becomes less than -20 dB (-20 Regions), calculated. Altering conditions such as sintering temperature, particle size and ratio ferrite powder composite resulted frequency dependencies that agree well with calculated...
We have investigated the microstructures and magnetic properties of L10 ordered FePt granular thin films prepared by ion beam sputtering subsequent annealing. As-deposited FePt–Al–O are composed fine spherical particles ∼2 nm diameter with disordered face-centered-cubic structure. These embedded in amorphous aluminum oxide matrix average spacing ∼1.3 nm, film exhibits superparamagnetism. By annealing above 650 °C, nanoparticles transform to phase grains coarsened ∼20 which results a high...
The microstructures of an Fe-31wt%Cr-23wt%Co ductile permanent magnet alloy after isothermal aging, thermomagnetic treatment, and step aging have been characterized by transmission electron microscopy measurement the Curie temperature. Isothermal itself produces undesirable microstructure. Aging at 600°C develops magnetic chromium-rich phase. a nonmagnetic phase dispersed within iron-rich effect treatment on microstructure is discussed in comparison with that Alnico alloys. Step deskable...
The magnetic properties during tempering of Fe‐ 30∼50wt% Cr‐ 10 ∼30wt% Co alloys, which consist bcc high‐temperature phase (α) obtained by quenching from 1300°C, have been measured. Alloys in a certain range composition showed desirable permanent‐magnetic step‐tempering following thermomagnetic treatment. An 31wt% 23wt% alloy, was tempered at 600°C for 2 hrs and subsequently 580°C 4 after an isothermal treatment 640°C 1/2 hr field 4000 Oe, had Br=11500 G, bHc=660 Oe (BH)max= 4.1 MGOe. In...
Microstructures of 50 nm thick FePt magnetic thin films deposited on Pt buffer layers with various thicknesses (0–500 nm) grown a Fe seeded MgO (100) substrate have been studied by transmission electron microscopy to correlate them properties. High density planar defects such as twin and antiphase boundary are present in the films. The twins observed these not {011} which commonly bulk magnet, but they {111} twins. morphology drastically change depending composition well thickness layer,...
Perpendicular magnetized epitaxial FePt(001) thin films were prepared by RF-magnetron sputtering. The long range order parameter S of the FePt layer was found to be ∼0.9. Very narrow X-ray rocking curves ( FWHM<1°) FePt(002) and Pt(200) peaks indicate that both layers are essentially single crystalline. With increasing Pt buffer thickness d , squareness M r / coercive force H C increase 100% 7.2 kOe, respectively. film has a |0.58°| peak at photon energy 2.0 eV (630 nm wavelength) in...
This paper describes the theoretical analysis of Barkhausen noises initiated in two different microstructures carbon steels, being consisted ferrite grains with or without dispersed cementites. The noise is generally evaluated by its RMS value, which sum induced voltage pulses caused magnetic flux change each microregion. In this an pulse approximated a gaussian pulse. relationships between values and steels are as follows, (RMS)=Cg.dg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The miscibility gap of the α phase in Fe-Cr-Co permanent magnet alloys is constructed using mechanical hardness and Curie temperature measurements. It found that Fe-Cr binary system develops into ternary system, addition cobalt raises decomposition temperature, extends difference concentrations between iron rich (α <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> ) chromium xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ). For...
The vertical section of the Fe-Cr-Co system at 15 wt%Co, 1 wt%Nb and wt%Al was constructed. extention α phase region sufficient enough to allow for solution treatment alloys 25∼30 wt%Cr content any temperature above <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> +α xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> miscibility gap. After step-tempering, their magnetic properties were given as Br = 11.5∼13 KG, Hc 500∼600 Oe (BH)max 4∼5...
With growing attention to sustainability and recognition of the impact global warming problems, energy supply consumption have become critically important. This paper presents construction a modeling platform accommodating cooperative management systems (EMSs), which virtually produces model smart city with distribution network (DN) by using wide range data obtained from real world. The involves models various EMSs, governing operation power system or controlling consumer-installed devices,...
The microstructure and magnetic property relationship in L10 ordered FePt–Al–O FePt–Ag granular thin films have been studied. As-sputtered films, composed of isolated fine spherical FePt particles ∼2 nm diameter with a disordered face-centered-cubic (fcc) structure, exhibit superparamagnetism. Annealing above 650 °C induces transformation from fcc structure to phase the become magnetically hard. microstructures these change greatly depending on film compositions annealing conditions, which...
Present works describe the developments low cost R-Fe-B sintered permanent magnets. Three different didymiums are chosen for mixtures of rare-earth elements. The studied alloy compositions Fe-(32.5–34.5)wt. %R-(1–1.6)wt. %B, where R elements didymium (Nd-10wt. %Pr), 5Ce-didymium (Nd-15%Pr-5%Ce), and 40 Ce-didymium (Nd-10%Pr-40%Ce). specimens were prepared by conventional powder metallurgical techniques. best magnetic properties obtained in this studies Br=13.2 kG, iHc=10.2 kOe, (BH)max=40...
The miscibility gap of an Fe-Cr-Co system is further examined by monitoring the microstructures and magnetic properties alloys. It shown that shape not parabolic but a peculiar shape, protruding to Fe side along Curie temperature. part protrusion called "ridge" because its resemblance. demonstrated alloys in ridge region can exhibit very good properties. An Fe-25%Cr-12%Co alloy gives as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Br =...
The apparatus for measurement of magnetooptical spectra using a polarization modulation technique has been improved to extend the short-wavelength limit about 200 nm in ultraviolet range. Short-wavelength characteristics light source, focusing system including mirrors and lenses, monochromator, polarizer analyzer were improved. techniques calibration Kerr rotation ellipticity also refined. With use newly designed system, FePt/Pt multilayers, as well FePt alloys different compositions...
The vertical sections of the Fe-Cr-Co system at 15wt%Co + 3wt%V, 5wt%V, and 3wt%V 2wt%Ti are constructed. extension α phase region 15%Co 5%V, 3%V 2%Ti is enough to allow for solution treatment alloys with 21∼23%Cr any temperature above <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\alpha_{1}+\alpha_{2}</tex> miscibility gap. After step-tempering, their magnetic properties given as Br=13.5 KG (1.35T), Hc=550 Oe (44kA/m) (BH)max=5.5 MGOe (44kJ/m...
The relationship between the microstructure and magnetic properties of heat treated Fe–23 wt%Cr–15 wt% Co–5 wt%V has been studied by transmission electron microscopy Lorentz microscopy. Three different treatments were adopted for present investigations, viz., (1) isothermal aging, (2) thermomagnetic treatment (TMT) + step-aging, (3) continuous cooling. It found that alloy are very sensitive to temperature TMT. Step-aging gave best properties, producing an elongated ferromagnetic phase, 300 Å...
It is reported that Nd-Fe-B magnetic powders prepared by utilizing the HDDR (hydrogenation, disproportionation, desorption, and recombination) phenomena exhibit high coercivity, addition of Co, Ga, Zr induces anisotropy in these powders. are caused heat treatment hydrogen (H treatment) subsequently vacuum (V treatment). Present works describe effects V-treatment conditions on properties Nd12.6Febal.CoxB6.0 (x=0–17.4) alloys. The V-treated at lower temperature show remanence no noticeable...
An improved method for the preparation of glycerinated Vorticella convallaria was investigated. The pretreatment living vorticellas with a medium containing 0.1% saponins and subsequent treatment an extraction 35% glycerol at about 0 degrees C satisfactory. equilibrium average length contractile stalks measured various free calcium concentrations in reaction medium. It found that element spasmoneme stalk is contracted by cooperative interaction involving least two ions.