A5030688466- Physics of Superconductivity and Magnetism
- Superconducting Materials and Applications
- Superconductivity in MgB2 and Alloys
- Magnetic Properties and Applications
- HVDC Systems and Fault Protection
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Advanced Surface Polishing Techniques
- Electric Motor Design and Analysis
- Frequency Control in Power Systems
- High-pressure geophysics and materials
- Magnetic Field Sensors Techniques
- Rare-earth and actinide compounds
- Corporate Taxation and Avoidance
- Intellectual Capital and Performance Analysis
- Non-Destructive Testing Techniques
- Metallurgical Processes and Thermodynamics
- Metallurgy and Material Forming
- Quantum and electron transport phenomena
- ZnO doping and properties
Kyushu Institute of Technology
2014-2024
Aso Iizuka Hospital
2024
Japan Science and Technology Agency
2013-2015
Kyushu University
1989-1990
Muon spin relaxation/rotation $(\ensuremath{\mu}\mathrm{SR})$ and magnetic susceptibility measurements were carried out on antiferromagnetic nanoparticles of CuO. Nanoparticles with center size around 5 nm prepared by ball-milling from single crystals CuO investigated using $\ensuremath{\mu}\mathrm{SR}$ measurements. In the $\ensuremath{\sim}5\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ assembly, ${T}_{\mathrm{N}}$ was reduced drastically to...
Abstract We have developed a polishing method for Cu CMP using superconductive assisted machining (SUAM) with levitated magnets in the air. SUAM enables non-contact pressure system by pinning effect of superconductivity to polish electroplated films backend processing. This offers key advantages: reduced dust generation, at room temperature, and precise control between pad wafer based on contact area holding force from effect. Results show that, same as conventional Cu-CMP, rate is...
Critical current densities in superconducting Y-Ba-Cu-O specimens with different sizes of 211 particles prepared by the melt process were measured under various magnetic fields and temperatures. Discussion is given on flux pinning properties background centers. At temperatures above 60 K, are expected to be dominant A rapid degradation critical density elevating temperature at low below 25 K seems attributed weak links specimens.
Addition of BaHfO3 (BHO) nano-rods as pinning centers into a GdBa2Cu3Oy (GdBCO) coated conductor dramatically improves the critical current properties in high magnetic fields. This is partly ascribed to strong flux these centers. In this paper it reported that improvement mainly caused by unexpected enhancement upper field, Bc2. The mechanism Bc2 not yet clear, although strain around interface between center and superconducting matrix or itself may scatter electrons. result suggests property...
Flux pinning properties were investigated by focusing on the origin of high peak critical current density and irreversibility field for Nd0.33Eu0.38Gd0.28Ba2Cu3Oy (NEG-123) bulk superconductors with addition 211 secondary phase particles volume fractions up to 10 mol%. It was found that a negative correlation exists between Jcp Bi various added phase. This suggests mechanisms determine are different. The do not contribute effect neither directly through condensation energy interaction nor...
Flux creep is theoretically investigated for a model of sinusoidal washboard potential in superconductors. An apparent pinning depth, U 0 * , defined by the relaxation rate shielding current density, found to be significantly smaller than given depth. In particular, reduces zero at temperature, while depth takes finite value. The effect form barrier on such significant flux low temperatures discussed.
An innovative superconducting DC power cable using high-temperature wires is introduced. The new design proposed to utilize the longitudinal magnetic field effect that was discovered about a half-century ago. It shown critical current density of wire could be significantly increased when superconductor in parallel configuration. empirically known force-free structure attained for flowing this case. In cable, outer layer twisted such way shielding region generates inner conductor. As result,...
It was theoretically shown by the authors that current-carrying capacity of superconducting DC power cable can be enhanced choosing a force-free configuration under parallel magnetic field produced current flowing back in outer shielding conductor.This experimentally checked for single layer using Bi-2223 tapes an applied field.It found took on peak value condition total including self-field.This shows proposed structure is suitable practical transmission.The possibility innovative with...
The weak link property in a QMG (quench and melt growth)-processed single-grain Y-Ba-Cu-O specimen was investigated by measuring the dependence of critical current density on temperature, history magnetic field application, its enhancement under longitudinal geometry. results show that weak-link regions still remain specimen. It is speculated these regions, which can transport superconducting currents at low temperatures, are degraded with increasing temperature lose superconductivity around...
The authors proposed an innovative superconducting dc power cable using the longitudinal magnetic field effect, i.e., a significant enhancement of critical current density superconductor in parallel field. It was expected that with high current-carrying capacity could be realized REBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O...
It was shown that the current-carrying capacity of a superconducting DC power cable could be dramatically increased using longitudinal magnetic field effect. That is, force-free structure assumed for conductor in to use significant enhancement critical current density parallel observed metallic superconductors. However, present commercial coated conductors decreases slightly with increasing field. Hence, fundamental design must changed obtain higher capacity. In spite poor field, it is still...