A5088539065- Rare-earth and actinide compounds
- Iron-based superconductors research
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Inorganic Chemistry and Materials
- Advanced Condensed Matter Physics
- GaN-based semiconductor devices and materials
- Particle accelerators and beam dynamics
- Magnetic properties of thin films
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Magnetic Properties and Applications
- Magnetism in coordination complexes
- Organic and Molecular Conductors Research
- Geomagnetism and Paleomagnetism Studies
- Particle Accelerators and Free-Electron Lasers
- Shape Memory Alloy Transformations
- Magnetic and Electromagnetic Effects
- Plasma Diagnostics and Applications
- Semiconductor materials and devices
- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Ga2O3 and related materials
- Advanced Photonic Communication Systems
Meijo University
2023-2025
Osaka University
2015-2024
Saitama Medical University
2024
Keio University
2024
National Institute for Fusion Science
2021-2023
The University of Tokyo
2002-2020
Toyota Technological Institute
2017-2020
Fracture Analysis Consultants (United States)
2020
Japan Organization of Occupational Health and Safety
2015-2017
Japan Industrial Safety and Health Association
2001-2014
We report the discovery of pressure-induced superconductivity in an antiferromagnet CeIrSi 3 , which lacks inversion symmetry tetragonal crystal structure. The Néel temperature T N = 5.0 K at ambient pressure decreases monotonically with increasing pressure, and becomes zero about 2.5 GPa. Superconductivity appears a wide region from 1.8 GPa to 3.5 GPa, relatively large superconduting transition sc 1.6 upper critical field H c2 (0) 11.1 indicating heavy-fermion superconductivity.
Multi-walled carbon nanotubes (MWCNTs) constitute one of the most promising types nanomaterials in industry today. With their increasing use, potential toxicity and carcinogenicity MWCNT needs to be evaluated bioassay studies using rodents. Since humans are mainly exposed by inhalation, we performed a 104-week study whole-body inhalation exposure chambers with fibrous straight type at concentrations 0, 0.02, 0.2, 2 mg/m3 male female F344 rats. Lung carcinomas, bronchiolo-alveolar carcinoma,...
Magnetization measurements in strong pulsed magnetic fields on single-crystal samples of the S=1 linear-chain Heisenberg antiferromagnet Ni(${\mathrm{C}}_{2}$${\mathrm{H}}_{8}$${\mathrm{H}}_{2}$${)}_{2}$${\mathrm{NO}}_{2}$(${\mathrm{ClO}}_{4}$) are reported. The magnetization is very small at low-field region and begins to increase sharply a finite field for all three principal axes. This evidence existence Haldane gap this compound.
We have studied Fermi surface properties of LaRhIn 5 and CeTIn (T: Co, Rh Ir) via the de Haas–van Alphen (dHvA) experiment. The a non-4 f reference compound is quasi-two dimensional, reflecting unique tetragonal crystal structure, which consistent with result FLAWP energy band calculations. an antiferromagnet CeRhIn similar to that , although cyclotron mass in roughly by one order larger than . Both surfaces are, however, different from those CeCoIn CeIrIn are well explained 4 -itinerant...
Magnetostriction measurements have been made in an ordered Fe3Pt single crystal with degree of order about 0.8, which exhibits a cubic-tetragonal martensitic transformation at 97 K. The specimen was cooled down to 4.2 K without magnetic field, and then field 4 T is applied the along 〈001〉 removed. As result, reversible giant magnetostriction 0.5% observed. This will be caused by rearrangement crystallographic domains, being three times as large that Terfenol-D (Fe2DyxTb1−x: typical...
We present the recent advances in Ce-based heavy fermion superconductivity. Heavy fermions are formed by competition between Ruderman–Kittel–Kasuya–Yosida interaction and Kondo effect. The application of pressure is useful for controlling electronic states antiferromagnets such as CeRh 2 Si , Ce Ni 3 Ge 5 CeIn CeRhIn CeIrSi . For these compounds, Néel temperature T N decreases with increasing reaches zero at quantum critical P c Superconductivity appears around In CeRu CeCoIn CePt Si,...
Superconductivity is ubiquitous as evidenced by the observation in many crystals including carrier-doped oxides and diamond. Amorphous solids are no exception. However, it remains to be discovered quasicrystals, which atoms ordered over long distances but not a periodically repeating arrangement. Here we report electrical resistivity, magnetization, specific-heat measurements of Al-Zn-Mg quasicrystal, presenting convincing evidence for emergence bulk superconductivity at very low transition...
We present recent advances in the magnetism and superconductivity of rare earth uranium compounds. Heavy fermions are formed on basis competition between RKKY interaction Kondo effect these The application pressure to compounds is useful control electronic states antiferromagnets CeRh 2 Si CeRhIn 5 , ferromagnet UGe . quadrupole or found be responsible for heavy PrFe 4 P 12 A rich variety superconducting properties demonstrated: CeCoIn vicinity a quantum critical point, coexistence...
With detailed experimental studies and hydrodynamics particle-in-cell simulations we investigate the role of prepulse in laser proton acceleration. The or pedestal (amplified spontaneous emission) can completely evaporate irradiated region a sufficiently thin foil; therefore, main part pulse interacts with an underdense plasma. multiparametric demonstrate that generates quasistatic magnetic field, which its turn produces long-lived charge separation electrostatic accelerating ions.
Neutron diffraction measurements have been performed on the cubic compound ${\mathrm{PrPb}}_{3}$ in a [001] magnetic field to examine quadrupolar ordering. Antiferromagnetic components with $q=(\frac{1}{2}\ifmmode\pm\else\textpm\fi{}\ensuremath{\delta}\text{ }\text{ }\frac{1}{2}\text{ }0)$, ($\frac{1}{2}\text{ }\frac{1}{2}\ifmmode\pm\else\textpm\fi{}\ensuremath{\delta}\text{ }0$) ($\ensuremath{\delta}\ensuremath{\approx}\frac{1}{8}$) are observed below transition temperature...
We measured low-temperature electrical resistivity in a magnetic field as function of pressure, and studied the superconducting property CeIrSi 3 with non-centrosymmetric tetragonal structure. is an antiferromagnet Néel temperature T N = 5.0 K at ambient but antiferromagnetic ordering disappears completely pressure P c 2.25 GPa. Superconductivity appears wide region from 1.8 to about 3.5 GPa, maximum transition sc ≃1.6 * ≃2.63 At around , upper critical H c2 for along [0 0 1] direction not...
Cancer development due to fiber-like straight type of multi-walled carbon nanotubes (MWCNTs) has raised concerns for human safety because its shape similar asbestos. To set concentrations MWCNT a rat carcinogenicity study, we conducted 13-week whole body inhalation study. F344 male and female rats, 6-week-old at the commencement were exposed by whole-body 0, 0.2, 1 5 mg/m3 with generation exposure system utilizing cyclone sieve method. Measured in chambers 0.20 ± 0.02, 1.01 0.11 5.02 0.25 13...
EuNi2P2 is known as a heavy fermion compound with an electronic specific heat coefficient γ=100 mJ/(K2 \(\cdot\)mol). We grew single crystals and studied their magnetic properties by measuring the electrical resistivity, susceptibility, high-field magnetization, heat, thermal expansion. The present state clarified to be based on Kondo effect in CeRu2Si2, revealing intensive shrinkage of volume below about 100 K temperature dependence dependences \(4f\)-electron contribution expansion Δ...
We studied the magnetic properties in a non-magnetic heavy-fermion compound CeIrIn 5 and an antiferromagnetic CeRhIn with tetragonal structure. High-field magnetization of shows weak metamagnetic transition around 420 kOe for field along [001] direction, while gradually increases up to 500 [110]. On other hand, we observed two-step perpendicular at 20 . The is x - y type. former indicates 1/cos θ dependence, where means tilted angle direction from (001) plane. From susceptibility high-field...
The effect of a magnetic field on martensitic transformations in Fe–Ni–Co–Ti and Fe3Pt shape memory alloys has been examined order to know field-induced transformation control crystallographic domain (variant) by field. Following results were obtained: (i) Magnetoelastic (martensites are induced only while is applied transformed back the parent phase when removed.) appears an ausaged Fe–Ni–Ti–Co alloy. critical for inducing magnetoelastic increases with increasing temperature. Volume...
R2Ti2O7 (R = Y and various rare earth elements) has pyrochlore type structure, which consists of two kinds three-dimensional networks individually formed by the corner-sharing R4and Ti4-tetrahedra, respectively. Due to this structural characteristic, magnetic moments at R sites are expected be frustrated, if their nearest neighbor interaction is antiferromagnetic. For Tb, value Weiss temperature w 19K, indicating Tb3þ have antiferromagnetic system does not exhibit clear evidence for...
Magnetic field-induced strain (MFIS) along the [001]P (the symbol “P” represents parent phase) direction due to conversion of martensite variants has been investigated for a disordered Fe–31.2Pd(at. %) single crystal and an ordered Fe3Pt exhibiting martensitic transformations from cubic phases tetragonal at 85 230 K, respectively. The tetragonality c/a Fe–31.2Pd 77 K is 0.940 that 14 0.945. When magnetic field applied phase direction, specimen expands contracts Fe3Pt, suggesting c axis hard...
Single crystals of LaIrSi 3 and CeIrSi were grown by the Czochralski pulling method in a tetra-arc furnace magnetic superconducting properties, together with superconductivity CeIr 1- x Co Si , clarified measuring electrical resistivity, specific heat, susceptibility, magnetization de Haas–van Alphen (dHvA) effect. From results dHvA experiment for Fermi surface is found to split into two surfaces due spin–orbit interaction arising from non-centrosymmetric crystal structure, which are...
A new multifunctional FePt nanoparticle (NP) exhibiting catalytic activity, magnetic properties, and water-compatibility, has been developed. The initial thermal decomposition of iron carbonyl (Fe(CO)5), followed by reduction platinum acetylacetonate (Pt(acac)2) in the presence oleic acid oleylamine produced NPs with Fe-rich core Pt-rich shell. hydrophobic were subsequently treated γ-cyclodextrin (γ-CD), which renders them water-dispersible rather than organic solvents. Characterization...
High-field specific heat measurements on BaCo(2)V(2)O(8), which is a good realization of an S=1/2 quasi-one-dimensional (1D) Ising-like antifferomagnet, have been performed in magnetic fields up to 12 T along the chain and at temperature down 200 mK. We found new ordered state field-induced phase above H(c) approximately 3.9 T. suggest that novel type incommensurate order, caused by quantum effect inherent quasi-1D antiferromagnet, appears phase.
We grew single crystals of non-centrosymmetric compounds CeTSi 3 and CeTGe (T: transition metal), studied the magnetic properties by measuring electrical resistivity, susceptibility magnetization. also effect pressure on electronic states in antiferromagnets Co, Rh, Ir) resistivity under pressure. No noticeable change Néel temperature was observed up to 8 GPa CeRhGe CeIrGe , which are far from quantum critical point. On other hand, CeCoGe strongly decreased as a function pressure,...
We grew a high-quality single crystal EuGa4 with the tetragonal structure by Ga self-flux method, and measured electrical resistivity, magnetic susceptibility, high-field magnetization, specific heat, thermoelectric power de Haas–van Alphen (dHvA) effect, together resistivity under pressure. is found to be Eu-divalent compound without anisotropy of susceptibility in paramagnetic state reveal same magnetization curve between \(H \parallel [100]\) [001] antiferromagnetic state, where easy-axis...
We succeeded in growing a single crystal of the Eu-divalent compound EuAl4 with BaAl4-type tetragonal structure by Al self-flux method and measured electrical resistivity, magnetic susceptibility, magnetization, specific heat, thermoelectric power. orders antiferromagnetically below TN1 = 15.4 K, three successive antiferromagnetic transitions at TN2 13.2 TN3 12.2 TN4 10.0 K. The latter two are first-order. corresponding magnetization curve indicates metamagnetic hystereses saturates above 16...