Hijiri Kito
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Hijiri Kito has a total of 53 co-authors. Here are the top co-authors by number of shared publications:
- Akira Iyo
National Institute of Advanced Industrial Science and Technology (AIST)
5 shared publications - Shigeyuki Ishida
National Institute of Advanced Industrial Science and Technology
4 shared publications - Yoshiyuki Yoshida
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
3 shared publications - Hiroshi Eisaki
Core Electronics Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
2 shared publications - Hiroshi Fujihisa
National Institute of Advanced Industrial Science and Technology (AIST)
2 shared publications - Yasumoto Tanaka
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
2 shared publications
Latest Publications
- 8 December 2022
- Published by IOP Publishing in Superconductor Science and Technology
- Vol. 36 (1) , 015009
Fabrication of multi-filament(Ba,A)Fe2As2 (A: Na, K) HIP round wires and a small superconducting coil
We report the fabrication and systematic characterizations of multi-filament (Ba,A)Fe2As2 (A: Na, K) round wires processed under high pressure. The evaluated transport and magnetic critical current density show clear core-number dependence. This trend originates from degradation of the superconducting core during the wire-drawing process, degradation of the concentric texturing of the core, and the enhanced sausaging effect of the core (revealed by x-ray tomography) as the number of cores increases. Details of the characterizations and suggestions for the improvement of the fabrication process are discussed. We constructed a superconducting magnet using seven-filament (Ba,K)Fe2As2 hot-isostatic pressed round wires. The generated magnetic field and critical current (I c) of the coils at 4.2 K are 1.0 kOe and 18 A, respectively. Measurements of the I c of short segments picked up from the coil show that there is enough room for improvements.
- 8 December 2022
- Published by IOP Publishing in Superconductor Science and Technology
- Vol. 36 (1) , 015009
Fabrication of multi-filament(Ba,A)Fe2As2 (A: Na, K) HIP round wires and a small superconducting coil
We report the fabrication and systematic characterizations of multi-filament (Ba,A)Fe2As2 (A: Na, K) round wires processed under high pressure. The evaluated transport and magnetic critical current density show clear core-number dependence. This trend originates from degradation of the superconducting core during the wire-drawing process, degradation of the concentric texturing of the core, and the enhanced sausaging effect of the core (revealed by x-ray tomography) as the number of cores increases. Details of the characterizations and suggestions for the improvement of the fabrication process are discussed. We constructed a superconducting magnet using seven-filament (Ba,K)Fe2As2 hot-isostatic pressed round wires. The generated magnetic field and critical current (I c) of the coils at 4.2 K are 1.0 kOe and 18 A, respectively. Measurements of the I c of short segments picked up from the coil show that there is enough room for improvements.
- 9 May 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 105 (19) , 195111
Direct observation of the electronic structure of the layered phosphide superconductorA layered phosphide superconductor, ( = Zr and Hf; = Se and S), is expected to be a foothold for the quest of new superconductors. Here, we report direct experimental observation of the electronic structure of (, 0.60, 0.75, and 0.85), using high-resolution bulk-sensitive hard x-ray photoemission spectroscopy. Core-level spectra of P show two distinct components separated by an energy of 1.2 eV. These reveal that the P atoms at two crystallographic sites have different valence charges, and , playing different chemical roles, and furthermore that the occupation ratio between them varies monotonically with . We observed valence-band features at , and eV together with a clear Fermi edge. The consistency with first-principles calculation indicates that the electronic states at Fermi level are mainly ascribed to the Zr band. Notably, a hump feature near the Fermi level shows an upward energy shift by 0.49 eV with decreasing from 0.85 to 0.55. The energy shifts of spectral features substantiate that replacing with serves as hole doping, shedding light on the tunability of . These findings on the electronic structure establish an essential basis for understanding the superconductivity in the system.- 9 May 2022
- Published by American Physical Society (APS) in Physical Review B
- Vol. 105 (19) , 195111
Direct observation of the electronic structure of the layered phosphide superconductorA layered phosphide superconductor, ( = Zr and Hf; = Se and S), is expected to be a foothold for the quest of new superconductors. Here, we report direct experimental observation of the electronic structure of (, 0.60, 0.75, and 0.85), using high-resolution bulk-sensitive hard x-ray photoemission spectroscopy. Core-level spectra of P show two distinct components separated by an energy of 1.2 eV. These reveal that the P atoms at two crystallographic sites have different valence charges, and , playing different chemical roles, and furthermore that the occupation ratio between them varies monotonically with . We observed valence-band features at , and eV together with a clear Fermi edge. The consistency with first-principles calculation indicates that the electronic states at Fermi level are mainly ascribed to the Zr band. Notably, a hump feature near the Fermi level shows an upward energy shift by 0.49 eV with decreasing from 0.85 to 0.55. The energy shifts of spectral features substantiate that replacing with serves as hole doping, shedding light on the tunability of . These findings on the electronic structure establish an essential basis for understanding the superconductivity in the system.- 15 July 2014
- Published by Physical Society of Japan in Journal of the Physical Society of Japan
- Vol. 83 (7)
New Intermetallic Ternary Phosphide ChalcogenideAP2−xXx(A= Zr, Hf;X= S, Se) Superconductors with PbFCl-Type Crystal Structure
We have synthesized a series of intermetallic ternary phosphide chalcogenide superconductors, AP2−xXx (A = Zr, Hf; X = S, Se), using the high-pressure synthesis technique. These materials have a PbFCl-type crystal structure (space group P4/nmm) when x is greater than 0.3. The superconducting transition temperature Tc changes systematically with x, yielding dome-like phase diagrams. The maximum Tc is achieved at approximately x = 0.7, at which point the Tc is 6.3 K for ZrP2−xSex (x = 0.75), 5.5 K for HfP2−xSex (x = 0.7), 5.0 K for ZrP2−xSx (x = 0.675), and 4.6 K for Hfp2−xSx (x = 0.5). They are typical type-II superconductors and the upper and lower critical fields are estimated to be 2.92 T at 0 K and 0.021 T at 2 K for ZrP2−xSex (x = 0.75), respectively.
- 15 July 2014
- Published by Physical Society of Japan in Journal of the Physical Society of Japan
- Vol. 83 (7)
New Intermetallic Ternary Phosphide ChalcogenideAP2−xXx(A= Zr, Hf;X= S, Se) Superconductors with PbFCl-Type Crystal Structure
We have synthesized a series of intermetallic ternary phosphide chalcogenide superconductors, AP2−xXx (A = Zr, Hf; X = S, Se), using the high-pressure synthesis technique. These materials have a PbFCl-type crystal structure (space group P4/nmm) when x is greater than 0.3. The superconducting transition temperature Tc changes systematically with x, yielding dome-like phase diagrams. The maximum Tc is achieved at approximately x = 0.7, at which point the Tc is 6.3 K for ZrP2−xSex (x = 0.75), 5.5 K for HfP2−xSex (x = 0.7), 5.0 K for ZrP2−xSx (x = 0.675), and 4.6 K for Hfp2−xSx (x = 0.5). They are typical type-II superconductors and the upper and lower critical fields are estimated to be 2.92 T at 0 K and 0.021 T at 2 K for ZrP2−xSex (x = 0.75), respectively.
- 1 December 2010
- Published by Elsevier in Physica C: Superconductivity and its Applications
- Vol. 470, S326-S327
Optical response of FeAs-based compounds
- 1 December 2010
- Published by Elsevier in Physica C: Superconductivity and its Applications
- Vol. 470, S326-S327
Optical response of FeAs-based compounds
- 2 June 2008
- Published by AIP Publishing in Applied Physics Letters
- Vol. 92 (22) , 222501
Simplest nontoxic double-layered cuprate Ba2CaCu2O4(O,F)2 superconductor with a transition temperature of 108K
We report synthesis and properties of the simplest double-layered cuprate superconductor . A superconducting transition temperature has been achieved as high as for a sample with a nominal fluorine content in . The is the highest among double-layer cuprates that are free of toxic elements such as Hg, Tl, and Pb so that the nontoxic will be promising for application. As decreases from approximately 2, the -axis length decreases and the increases from . The material is underdoped at large and as decreases, the doping moves toward an optimally doped state.- 2 June 2008
- Published by AIP Publishing in Applied Physics Letters
- Vol. 92 (22) , 222501
Simplest nontoxic double-layered cuprate Ba2CaCu2O4(O,F)2 superconductor with a transition temperature of 108K
We report synthesis and properties of the simplest double-layered cuprate superconductor . A superconducting transition temperature has been achieved as high as for a sample with a nominal fluorine content in . The is the highest among double-layer cuprates that are free of toxic elements such as Hg, Tl, and Pb so that the nontoxic will be promising for application. As decreases from approximately 2, the -axis length decreases and the increases from . The material is underdoped at large and as decreases, the doping moves toward an optimally doped state.- 20 June 2007
- Published by Wiley in ChemInform
- Vol. 38 (28)
NMR Initiatives on Understanding High‐temperature Superconductivity
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
- 20 June 2007
- Published by Wiley in ChemInform
- Vol. 38 (28)
NMR Initiatives on Understanding High‐temperature Superconductivity
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
- 6 November 2003
- Published by American Physical Society (APS) in Physical Review B
- Vol. 68 (17) , 174506
Comparative study of the electronic structure ofandX-ray photoemission spectroscopy is used to compare the electronic structures of and The B core levels in high-quality and exhibit a single asymmetric peak typical of a metallic boride. The Mg core level shows a single peak with negligible intensity in charge-transfer satellites and no correlation effects. The Mg and B core-level spectra exhibit a broad bulk plasmon feature centered at about 22 eV from the main peak, in good accord with calculations. The measured valence bands are consistent with band-structure calculations indicating a higher density of states (DOS) at for compared to The high in is due to p-derived DOS, while is dominated by d-derived states at- 6 November 2003
- Published by American Physical Society (APS) in Physical Review B
- Vol. 68 (17) , 174506
Comparative study of the electronic structure ofandX-ray photoemission spectroscopy is used to compare the electronic structures of and The B core levels in high-quality and exhibit a single asymmetric peak typical of a metallic boride. The Mg core level shows a single peak with negligible intensity in charge-transfer satellites and no correlation effects. The Mg and B core-level spectra exhibit a broad bulk plasmon feature centered at about 22 eV from the main peak, in good accord with calculations. The measured valence bands are consistent with band-structure calculations indicating a higher density of states (DOS) at for compared to The high in is due to p-derived DOS, while is dominated by d-derived states at