Oral
High-Pressure Synthesis of Superconductive Hydride | Authors: Katsuya Shimizu (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Harushige Nakao (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Mari Einaga (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Masafumi Sakata (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Masaomi Kitagaki (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Daichi Takeda (1 - 1 - KYOKUGEN, Center for Science and Technology under Extreme Conditions, Graduate School of Engineering Science, Osaka University) ; Saori Kawaguchi (2 - JASRI) ; Naohisa Hirao (2 - JASRI) ; Yasuo Ohishi (2 - JASRI) |
Abstract: Superconductivity exceeding 200 K was recently reported in the highly compressed hydrides [1-3]. Here we report the investigation of the superconductivity of them by several synthesis methods. An originally designed transport preparation in the gasket was used in a laser-heating diamond-anvil cell (DAC). In the case of sulfur hydride (H3S) which was synthesized by a low-temperature pathway (compression at low temperature ~ 200 K) and showed the superconductivity with the transition temperature of 200 K at around 150 GPa [1]. We found that the superconductive hydride was synthesized through the chemical reaction of 3H2S → 2H3S + S in this pathway by using the synchrotron x-ray in SPring-8 [4]. We succeeded in the synthesis of superconductive H3S from elemental sulfur and hydrogen. Pure sulfur was compressed with hydrogen in the DAC at room temperature up to 150 GPa. The sulfur was heated by an infrared laser to initiate the chemical reaction (2S + 3H2 → 2H3S). A drop of the electrical resistance which may correspond to the superconductivity at 200 K was observed. This method is applicable to the synthesis of other superconductive hydrides. The results of the direct synthesis using elemental hydrogen and other hydrides as the hydrogen source will be reviewed. This work was supported by JSPS KAKENHI Grant Number 26000006.
References:
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[4] M. Einaga, M. Sakata, T. Ishikawa, K. Shimizu, M. I. Eremets, A. P. Drozdov, I. A. Troyan, N. Hirao, Y. Ohishi, Nature Phys. 12, 835 (2016).
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