A5052664431- Fullerene Chemistry and Applications
- Boron and Carbon Nanomaterials Research
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- High-pressure geophysics and materials
- Carbon Nanotubes in Composites
- Inorganic Chemistry and Materials
- Superconductivity in MgB2 and Alloys
- Iron-based superconductors research
- Advanced Chemical Physics Studies
- Rare-earth and actinide compounds
- Diamond and Carbon-based Materials Research
- Thermal Expansion and Ionic Conductivity
- Organic and Molecular Conductors Research
- Magnetism in coordination complexes
- Molecular Junctions and Nanostructures
- Solid-state spectroscopy and crystallography
- X-ray Diffraction in Crystallography
- Synthesis and Properties of Aromatic Compounds
- Crystal Structures and Properties
- Muon and positron interactions and applications
- Advanced Physical and Chemical Molecular Interactions
- Crystallization and Solubility Studies
Tokyo Metropolitan University
2023-2024
Osaka Metropolitan University
2023-2024
Kyoto University of Advanced Science
2023-2024
Jožef Stefan Institute
2002-2024
Tohoku University
2009-2023
Advanced Institute of Materials Science
2014-2023
Osaka Prefecture University
2011-2022
Osaka Health Science University
2020
Graduate School USA
2020
Institute for Materials Research, Tohoku University
1996-2019
High-resolution powder neutron diffraction has been used to study the crystal structure of fullerence C60 in temperature range 5 K 320 K. Solid adopts a cubic at all temperatures. The experimental data provide clear evidence continuous phase transition ca. 90 and confirm existence first-order 260 In high-temperature face-centred-cubic (T > K), molecules are completely orientationally disordered, undergoing reorientation. Below K, interpretation is consistent with uniaxial jump reorientation...
FeSe with the PbO structure is a key member of family new high-$T_c$ iron pnictide and chalcogenide superconductors, as while it possesses basic layered structural motif edge-sharing distorted FeSe$_4$ tetrahedra, lacks interleaved ion spacers or charge-reservoir layers. We find that application hydrostatic pressure first rapidly increases $T_c$ which attains broad maximum 37 K at $\sim$7 GPa (this one highest ever reported for binary solid) before decreasing to 6 upon further compression...
Isotropic nearly zero thermal expansion (i.e., negligible volume change) is reported in a large temperature range for Fe[Co(CN)6], member of the Prussian blue family with electronically active metal sublattices and cubic framework structure built by cyanide-bridged network octahedral units. Suitable selection ions interstitial units could allow such anomalous behavior to be combined variety unusual electronic, optical, magnetic properties exhibited analogues.
The body-centered cubic A15-structured cesium fulleride Cs3C60 is not superconducting at ambient pressure and free from disorder, unlike the well-studied face-centered A3C60 alkali metal superconductors. We found that in Cs3C60, where molecular valences are precisely assigned, state 38 kelvin emerges directly a localized electron antiferromagnetic insulating with application of pressure. This transition maintains threefold degeneracy active orbitals both competing electronic states; it thus...
The newly discovered superconductor FeSe1−x (x≈ 0.08, Tconset≈ 13.5 K at ambient pressure rising to 27 1.48 GPa) exhibits a structural phase transition from tetragonal orthorhombic below 70 pressure—the crystal structure in the superconducting state shows remarkable similarities that of REFeAsO1−xFx (RE = rare earth) superconductors.
We investigate the normal state of "11" iron-based superconductor FeSe0.42Te0.58 by angle-resolved photoemission. Our data reveal a highly renormalized quasiparticle dispersion characteristic strongly correlated metal. find sheet dependent effective carrier masses between approximately 3 and 16m{e} corresponding to mass enhancement over band structure values m{*}/m{band} 6-20. This is nearly an order magnitude higher than renormalization reported previously for iron-arsenide superconductors...
Understanding the relationship between superconducting, neighboring insulating, and normal metallic state above T c is a major challenge for all unconventional superconductors. The molecular A3C60 fulleride superconductors have parent antiferromagnetic insulator in common with atom-based cuprates, but here, C60 (3-) electronic structure controls geometry spin of structural building unit via on-molecule Jahn-Teller effect. We identify metal as fluctuating microscopically heterogeneous...
Abstract Commonly available heat-storage materials cannot usually store the energy for a prolonged period. If solid material could conserve accumulated thermal energy, then its application potential is considerably widened. Here we report phase transition that can latent heat in wide temperature range, T <530 K and release on of pressure. This stripe-type lambda-trititanium pentoxide, λ-Ti 3 O 5 , which exhibits solid–solid to beta-trititanium β-Ti . The pressure conversion extremely...
We report that the ternary MgB2-xCx compounds adopt an isostructural AlB2-type hexagonal structure in a relatively small range of nominal carbon concentration, x<0.1. The lattice parameter decreases almost linearly with increasing content x, while c remains unchanged, indicating is exclusively substituted boron honeycomb layer without affecting interlayer interactions. superconducting transition temperature Tc, determined by magnetometry experiments, also quasilinearly as function...
The crystal structure of superconducting Na(2)CsC(60) was studied by high-resolution powder neutron diffraction between 1.6 and 425 K. Contrary to the literature, at low temperatures is primitive cubic [See equation in PDF file], isostructural with pristine C(60). Anticlockwise rotation C(60) units 98 degrees about [111] allows simultaneous optimization C(60)-C(60) alkali-fulleride interactions. Optimal Na(+)-C(60)(3-) coordination achieved each sodium ion located above one hexagon face...
The fluorine-doped rare-earth iron oxyarsenides ${\text{REFeAsO}}_{1\ensuremath{-}x}{\text{F}}_{x}$ ($\text{RE}=\text{rare}$ earth) have recently emerged as a new family of high-temperature superconductors with transition temperatures $({T}_{c})$ high 55 K. Here we use high-resolution synchrotron x-ray diffraction to study the structural properties ${\text{SmFeAsO}}_{1\ensuremath{-}x}{\text{F}}_{x}$ $(0\ensuremath{\le}x\ensuremath{\le}0.20)$ in which superconductivity emerges near...
The ternary iron chalcogenide, Fe1.03Se0.57Te0.43 is a member of the recently discovered family Fe-based superconductors with an ambient pressure Tc 13.9 K and simple structure comprising layers edge-sharing distorted Fe(Se/Te)4 tetrahedra separated by van der Waals gap. Here we study relationship between its structural electronic responses to application pressure. depends sensitively on applied attaining broad maximum 23.3 at ∼3 GPa. Further compression 12 GPa leads metallic but...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTUnconventional Bonding of Azafullerenes: Theory and ExperimentWanda Andreoni, Alessandro Curioni, Károly Holczer, Kosmas Prassides, Majid Keshavarz-K., Jan-Cornelis Hummelen, Fred WudlView Author Information IBM Research Division, Zurich Laboratory CH-8803 Rüschlikon, Switzerland Scuola Normale Superiore, I-56126 Pisa, Italy Department Physics, University California Los Angeles, 90024 School Chemistry, Physics Environmental Science Sussex,...
The zero-field muon spin relaxation technique has been used in the direct observation of spontaneous magnetic order below a Curie temperature ( T c ) ∼16.1 kelvin fullerene charge-transfer salt (tetrakisdimethylaminoethylene)C 60 [(TDAE)C ]. Coherent ordering electronic moments leads to local field 68(1) gauss at site 3.2 (parentheses indicate error last digit). Substantial spatially inhomogeneous effects are manifested distribution fields, whose width amounts 48(2) same temperature....