1. Bulk superconductivity in Pb-substituted BiS$_{\bf 2}$-based compounds studied by hard-x-ray spectroscopy
- Author
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Yamasaki, A., Oguni, T., Hayashida, T., Miyazaki, K., Tanaka, N., Nakagawa, K., Tamura, K., Mimura, K., Kawamura, N., Fujiwara, H., Nozue, G., Ose, A., Kanai-Nakata, Y., Higashiya, A., Hamamoto, S., Tamasaku, K., Yabashi, M., Ishikawa, T., Imada, S., Sekiyama, A., Sakata, H., and Demura, S.
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Condensed Matter - Superconductivity - Abstract
In this study, we investigate the bulk electronic structure of Pb-substituted LaO$_{0.5}$F$_{0.5}$BiS$_2$ single crystals, using two types of hard-x-ray spectroscopy. High-energy-resolution fluorescence-detected x-ray absorption spectroscopy revealed a spectral change at low temperatures. Using density functional theory (DFT) simulations, we find that the temperature-induced change originates from a structural phase transition, similar to the pressure-induced transition in LaO$_{0.5}$F$_{0.5}$BiS$_2$. This finding suggests that the mechanism of bulk superconductivity induced by Pb substitution is the same as that under high pressure. Furthermore, a novel low-valence state with a mixture of divalent and trivalent Bi ions is discovered using hard x-ray photoemission spectroscopy with the aid of DFT calculations., Comment: 8 pages, 6 figures, 1 table
- Published
- 2023
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