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arXiv · 2211.05355

Electronic phase diagram in Te-annealed superconducting FeTe$_{1-x}$Se$_x$ revealed by magnetic susceptibility

Takenori Fujii·Yu Uezono·Takumi Otsuka·Shotaro Hagisawa·Takao Watanabe
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Abstract

Knowledge of the doping (x)-temperature (T) phase diagram of Fe-based superconductors is crucial in understanding the mechanism of high transition temperature superconductivity. Here, we measured the Se doping dependence of the magnetic susceptibility for Te-annealed FeTe$_{1-x}$Se$_x$. Two characteristic temperatures $T^*_{\chi}$ and $T^{**}_{\chi}$ were observed in the temperature dependence of magnetic susceptibility, where the magnetic susceptibility decreased below T$^{**}_{\chi}$ and tended to increase with further decreasing temperature below T$^*_{\chi}$. The decrease in magnetic susceptibility below T$^{**}_{\chi}$ is considered to be due to the opening of the pseudogap. Whereas the increase in magnetic susceptibility below T$^*_{\chi}$ is attributed to the increase in the carrier concentration of electrons. Furthermore, we found the large superconducting fluctuation, which may be related to BCS-BEC crossover.

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Takenori Fujii, Yu Uezono, Takumi Otsuka, Shotaro Hagisawa, Takao Watanabe. 2022-11-10. Electronic phase diagram in Te-annealed superconducting FeTe$_{1-x}$Se$_x$ revealed by magnetic susceptibility. https://doi.org/10.7566/jpscp.38.011027

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