Ryo Matsumoto
National Institute for Materials Science
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Publication
Featured researches published by Ryo Matsumoto.
Review of Scientific Instruments | 2016
Ryo Matsumoto; Yosuke Sasama; Masaya Fujioka; Tetsuo Irifune; Masashi Tanaka; Takahide Yamaguchi; Hiroyuki Takeya; Yoshihiko Takano
A novel diamond anvil cell suitable for electrical transport measurements under high pressure has been developed. A boron-doped metallic diamond film was deposited as an electrode on a nano-polycrystalline diamond anvil using a microwave plasma-assisted chemical vapor deposition technique combined with electron beam lithography. The maximum pressure that can be achieved by this assembly is above 30 GPa. We report electrical transport measurements of Pb up to 8 GPa. The boron-doped metallic diamond electrodes showed no signs of degradation after repeated compression.
Solid State Communications | 2018
Aichi Yamashita; Ryo Matsumoto; Masashi Tanaka; Hiroshi Hara; Kazumasa Iida; B. Holzapfel; Hiroyuki Takeya; Yoshihiko Takano
Abstract Superconducting FeSe films were electrochemically deposited on rolling-assisted biaxially textured substrate (RABiTS) tape. We observed zero resistivity in the as-electrodeposited FeSe film prepared on the RABiTS when the appropriate voltage was applied while it was dipped into the solution. When the RABiTS tape was dipped in the solution without applying voltage, a thin Se film was deposited on the substrate. The compositional ratio of the FeSe film got closer to the stoichiometric ratio with decreasing the dipping time before applying voltage.
Applied Physics Express | 2017
Ryo Matsumoto; Hirotsugu Iwata; Aichi Yamashita; Hiroshi Hara; Gen Nishijima; Masashi Tanaka; Hiroyuki Takeya; Yoshihiko Takano
Superconducting joints between NbTi and Bi2Sr2Ca2Cu3O10 superconducting wires were successfully fabricated using Bi-added PbSn solders with an in situ sheath-dissolution technique without a removal process for the sheath materials. A backscattered electron image and an energy-dispersive X-ray spectroscopy analysis of the cross-sectional plane of the joints revealed that the joints using Bi-added PbSn solder had a homogeneous morphology with tiny non-superconducting islands. The superconducting joints exhibited high critical currents above 200 A in self-field and 50 A under an applied magnetic field of 5 kOe.
Journal of the Physical Society of Japan | 2015
Masaya Fujioka; Ryo Matsumoto; Takuma Yamaki; Saleem J. Denholme; Masashi Tanaka; Hiroyuki Takeya; Takahide Yamaguchi; Hiroki Takahashi; Yoshihiko Takano
A pressure-induced phase transition in LaO0.5F0.5BiSeS is demonstrated by performing resistance measurements with a diamond anvil cell. The superconducting transition temperature (Tc) of LaO0.5F0.5BiSeS changes from a low-Tc phase (4.9 K) to a high-Tc phase (7 K) owing to the application of pressure up to 5.1 GPa.
Journal of Asian Ceramic Societies | 2017
Akira Miura; Satoshi Ishii; Masanori Nagao; Ryo Matsumoto; Yoshihiko Takano; Satoshi Watauchi; Isao Tanaka; Nataly Carolina Rosero-Navarro; Kiyoharu Tadanaga
Abstract LaO0.5F0.5BiS2 nanosheets were produced by ultrasonification. A slightly reddish colloidal suspension was obtained by ultrasonification of LaO0.5F0.5BiS2 powder in ethanol. Transmission electron microscope (TEM) images of the dried suspension indicated the nanosheet morphology of LaO0.5F0.5BiS2, and the electron diffraction spots indicated 4-fold symmetry. The thickness of the sheets was 2–6 nm, which corresponded to 2–4 unit cells of the c-axis of LaO0.5F0.5BiS2.
Japanese Journal of Applied Physics | 2017
Ryo Matsumoto; Tetsuo Irifune; Masashi Tanaka; Hiroyuki Takeya; Yoshihiko Takano
A novel diamond anvil cell specialized for resistivity measurements under high pressure have been developed. Boron-doped metallic diamond electrodes were deposited onto a nano-polycrystalline diamond anvil using a microwave plasma-assisted chemical vapor deposition technique combined with electron beam lithography. The various designs of boron-doped metallic diamond electrodes were demonstrated, and they showed no signs of degradation after repeated compression.
Crystal Growth & Design | 2016
Masanori Nagao; Masashi Tanaka; Ryo Matsumoto; Hiromi Tanaka; Satoshi Watauchi; Yoshihiko Takano; Isao Tanaka
Journal of Electron Spectroscopy and Related Phenomena | 2016
Ryo Matsumoto; Yugo Nishizawa; Noriyuki Kataoka; Hiromi Tanaka; Hideki Yoshikawa; Shigeo Tanuma; Kazuhiro Yoshihara
Journal of Alloys and Compounds | 2017
Masashi Tanaka; Masanori Nagao; Ryo Matsumoto; Noriyuki Kataoka; Ikuo Ueta; Hiromi Tanaka; Satoshi Watauchi; Isao Tanaka; Yoshihiko Takano
arXiv: Superconductivity | 2018
Ryo Matsumoto; Hiroshi Hara; Hiromi Tanaka; Kazuki Nakamura; Noriyuki Kataoka; Sayaka Yamamoto; Aichi Yamashita; Shintaro Adachi; Tetsuo Irifune; Hiroyuki Takeya; Yoshihiko Takano