A5101483130- Rare-earth and actinide compounds
- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Magnetic Properties of Alloys
- Advanced Condensed Matter Physics
- Inorganic Chemistry and Materials
- Nuclear Materials and Properties
- Magnetic and transport properties of perovskites and related materials
- High-pressure geophysics and materials
- Advanced Chemical Physics Studies
- Advanced MRI Techniques and Applications
- Radioactive element chemistry and processing
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Organic and Molecular Conductors Research
- Thermodynamic and Structural Properties of Metals and Alloys
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- NMR spectroscopy and applications
- Medical Imaging Techniques and Applications
- Theoretical and Computational Physics
Japan Atomic Energy Agency
2015-2024
Advanced Science Research Center
2014-2023
Chiba University
2012-2014
Tohoku University
1999-2011
Hitachi (United Kingdom)
1995-2010
Japan Science and Technology Agency
2010
Hitachi (Japan)
1993-2009
University of Tsukuba
2009
Hyogo Medical University
2006
Osaka University
2000-2005
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.
The mysterious hidden-order phase of a heavy-fermion compound may be an electronic nematic state.
${}^{195}\mathrm{Pt}$ Knight shift (KS) measurements covering the superconducting multiple phases for major field ( $H$) orientations have been carried out on high-quality single crystal ${\mathrm{UPt}}_{3}$. For $H>5$ kOe, KS does not change below transition temperature ${T}_{c}$ down to 28 mK, regardless of orientations, which provides evidence that odd-parity superconductivity with parallel spin pairing is realized. By contrast, decreases ${H}_{b}\ensuremath{\parallel}b$ axis and...
The temperature dependence of the ${}^{195}\mathrm{Pt}$ Knight shift, $K$, for high quality single crystal ${\mathrm{UPt}}_{3}$ has been measured down to $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}28\mathrm{mK}$ in applied magnetic fields parallel and perpendicular hexagonal $c$ axis. No change $K$'s found across superconducting transition ${T}_{c}$ 28 mK regardless directions independent multiphases. It is demonstrated that odd-parity superconductor with spin pairing following...
We report the discovery of pressure-induced superconductivity in ferromagnetic UIr, which lacks inversion symmetry crystal structure. The Curie temperature TC1 = 46 K at ambient pressure decreases with increasing pressure, reaching a value 11 1.5 GPa. It presumably further up to about Pc1 1.7 region named 'F1' exists Pc1. A second magnetic phase 'F2' low moment appears range from 1.9 2.4 In phase, transition TC2 18 GPa approximately zero PC2 2.6–2.7 this critical region, below Tsc 0.14 K.
The molten salt flux method is applied as a synthetic route for the single crystals of spin-triplet superconductor ${\mathrm{UTe}}_{2}$. under an optimized growth condition with excess uranium exhibit superconducting transition at ${T}_{\mathrm{c}}=2.1\phantom{\rule{4pt}{0ex}}\mathrm{K}$, which highest ${T}_{\mathrm{c}}$ reported this compound. obtained show remarkably large residual resistivity ratio respect to room temperature value and small electronic contribution in specific heat well...
Pressure-induced superconductivity is found in UIr without inversion symmetry. The pressure–temperature phase diagram has been investigated by means of the electrical resistivity and magnetization measurements under high pressure. consists two magnetic phases, Ising-like ferromagnetic (FM1) at low pressures another (FM2) with small component along [10\bar1] direction pressures. Superconductivity observed narrow pressure range near disappearance point FM2 phase, where temperature dependence...
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...
The endohedral nature of dimetallofullerene S${\mathrm{c}}_{2}$@${\mathrm{C}}_{84}$ is determined for the first time by a method which combination maximum entropy (MEM) and Rietveld refinement from synchrotron powder diffraction data. obtained MEM charge density clearly shows ${D}_{2d}$-symmetry cage structure, indicating rotation molecules in solid state almost quenched even at room temperature. From density, encapsulated Sc-Sc distance nearest Sc-C are 3.9(1) 2.4(1) \AA{}, respectively.
We succeeded in growing a new transuranium compound NpPd 5 Al 2 with the tetragonal crystal structure by Pb-flux method, and measured electrical resistivity, specific heat, magnetic susceptibility magnetization. is found to be paramagnetic heavy-fermion superconductor strong coupling Δ C /γ T c = 2.33 [ =4.9 K γ= 200 mJ/(K ·mol)]. The upper critical field H c2 at 0 large highly anisotropic: (0) =37 kOe for ∥[100] =143 ∥[001]. strongly suppressed field, magnetization curve indicates step-like...
The endohedral structure of tri-metallofullerene ${\mathrm{Sc}}_{3}@{\mathrm{C}}_{82}$ is determined by the maximum entropy method (MEM) combined with Rietveld using synchrotron radiation powder data. result reveals for first time that Sc atoms are encapsulated in form a triangle cluster inside ${\mathrm{C}}_{3V}\ensuremath{-}{\mathrm{C}}_{82}$ fullerene. charge state encaged trimer also as ${\mathrm{Sc}}_{3}^{3+}@{\mathrm{C}}_{82}^{3\ensuremath{-}}$ from MEM density. Sc-Sc distance...
Results of dc magnetization, magnetic relaxation, specific heat, and electrical resistivity measurements on a well-annealed polycrystalline ${\mathrm{U}}_{2}{\mathrm{PdSi}}_{3}$ sample are reported. The temperature dependence the magnetization exhibits cusp at characteristic ${T}_{f}$ that strongly depends applied field. Below ${T}_{f},$ relaxation reveal decay isothermal remanent vs time is drastically slower than above ${T}_{f}.$ No anomalies around observed in heat data, which rules out...
Clinical studies of cerebral achromatopsia have suggested a colour centre in the human fusiform gyrus. By using functional magnetic resonance imaging, we examined whether gyrus shows activity correlated with perception colour. We tested three stimulus conditions which subject maintained fixation: (i) circular array six coloured circles; (ii) same as except that each circle is equiluminant grey its counterpart; and (iii) plus clockwise shift circles to neighbouring positions every 1 s. After...
CeRu2 and 2H-NbSe2 display remarkable similarities in their magnetic response, reflecting the manner which weakly pinned flux line lattice (FLL) loses spatial order Peak Effect (PE) regime. The discontinuous change screening response near onset of PE history dependence it are attributed to a disorder-induced fracturing transition FLL, as an alternative scenario involving appearance modulation superconducting parameter CeRu2.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXT13C-NMR Study on the Structure of Isolated Sc2@C84 MetallofullereneEtsuji Yamamoto, Masataka Tansho, Tetsuo Tomiyama, Hisanori Shinohara, Hironori Kawahara, and Yuji KobayashiView Author Information Department Chemistry, Nagoya University 464-01, Japan Analytical Instruments Service Division, Osaka Center JEOL Datum Co. Ltd., 532, Institute for Protein Research, 565, Cite this: J. Am. Chem. Soc. 1996, 118, 9, 2293–2294Publication Date...
Correlations between T1 and T2 relaxation times water electrolyte content in the normal ischemic rat gerbil brains were studied by means of both nuclear magnetic resonance (NMR) spectroscopic imaging methods. In experiment on excised brains, was linearly dependent tissue prolonged edematous to a greater extent than expected an increase content, showing that possesses sensitivity for edema identification localization. Changes Na+ K+ mattered little prolongation times. Serial NMR insulted with...
The field-orientation dependent thermal conductivity of the heavy-fermion superconductor UPt3 was measured down to very low temperatures and under magnetic fields throughout distinct superconducting phases: B C phases. In phase, a striking twofold oscillation within basal plane is resolved reflecting gap structure with line node along axis. Moreover, we find an abrupt vanishing across transition as clear indication change symmetries. We also identify extra two nodes below above equator in...
The detail of electronic structures near the Fermi level in ${\text{URu}}_{2}{\text{Si}}_{2}$ has been investigated employing state-of-art laser angle-resolved photoemission spectroscopy. observation a narrow dispersive band ordered state as well its absence Rh-substituted sample strongly suggest that emergence is clear signature hidden-order transition. temperature dependence band, which appears at onset transition, invokes occurrence periodicity modification state, shown for first time by...
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 report the first observation of cyclotron resonance in hidden-order phase ultra-clean URu$_2$Si$_2$ crystals, which allows full determination angle-dependent electron-mass structure main Fermi-surface sheets. find an anomalous splitting sharpest line under in-plane magnetic-field rotation. This is most naturally explained by domain formation, breaks fourfold rotational symmetry underlying tetragonal lattice. The results reveal emergence mass anisotropy with hot spots along [110]...
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...
In order to elucidate the nature of exotic ordered phase NpO2 below T(0)=26 K, we have initiated first 17O-NMR measurements on this system. From spectrum, occurrence two inequivalent oxygen sites has been confirmed T0. It also shown that characteristic features hyperfine interaction at are well explained by invoking a with field-induced antiferromagnetic moments which appear as result triple-q antiferroquadrupolar order. The NMR findings strongly support longitudinal multipole structure in NpO2.
We have measured the specific heat and magnetization in superconducting mixed state of CeRu 2 at low temperatures high magnetic fields. clarified a rich variety properties such as temperature dependence electronic Maki parameters κ 1 , 3 . From these experimental results, is concluded to be BCS-type superconductivity. Nevertheless, interesting field 0.5 K, indicating \(\sqrt{H}\) like behavior fields H -linear up upper critical 50 kOe. This characteristic discussed on basis microscopic...