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arXiv · 1811.01151

Pressure-induced Insulator to Metal Transition of Mixed Valence Compound Ce(O,F)SbS$_{2}$

Ryo Matsumoto·Masanori Nagao·Masayuki Ochi·Hiromi Tanaka·Hiroshi Hara·Shintaro Adachi·Kazuki Nakamura·Ryo Murakami·Sayaka Yamamoto·Tetsuo Irifune·Hiroyuki Takeya·Isao Tanaka·Kazuhiko Kuroki·Yoshihiko Takano
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Abstract

Transport properties of Ce$_{0.85}$F0.15SbS$_{2}$ and undoped CeOSbS$_{2}$ under high pressure were investigated experimentally and theoretically. Electrical resistivity measurements of the Ce$_{0.85}$F0.15SbS$_{2}$ single crystals were performed under various high pressures using a diamond anvil cell with boron-doped diamond electrodes. The samples showed the insulator to metal transition by applying high pressure up to 30-40 GPa. On the other hand, the undoped CeOSbS$_{2}$ showed almost same transport property with the F-doped sample under high pressure. The valence state analysis using X-ray photoelectron spectroscopy revealed a simple valence state of Ce3+ in Ce$_{0.85}$F0.15SbS$_{2}$ and mixed valence state between Ce3+ and Ce4+ in undoped CeOSbS$_{2}$. The valence fluctuation in Ce carried out the comparable transport nature in the both samples. A band calculation suggests that the undoped CeOSbS$_{2}$ could be metallic under high pressure of 30 GPa in accordance with the experimental results. A superior thermoelectric property of power factor in CeOSbS$_{2}$ was estimated under high pressure around 20 GPa in comparison with that of ambient pressure.

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Ryo Matsumoto, Masanori Nagao, Masayuki Ochi, Hiromi Tanaka, Hiroshi Hara, Shintaro Adachi, Kazuki Nakamura, Ryo Murakami, Sayaka Yamamoto, Tetsuo Irifune, Hiroyuki Takeya, Isao Tanaka, Kazuhiko Kuroki, Yoshihiko Takano. 2018-11-03. Pressure-induced Insulator to Metal Transition of Mixed Valence Compound Ce(O,F)SbS$_{2}$. https://doi.org/10.1063/1.5079765

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