Origin of Pressure-induced Superconducting Phase in KxFe2−ySe2 studied by Synchrotron X-ray Diffraction and Spectroscopy

  title={Origin of Pressure-induced Superconducting Phase in KxFe2−ySe2 studied by Synchrotron X-ray Diffraction and Spectroscopy},
  author={Yoshiya Yamamoto and Hitoshi Yamaoka and Masashi Tanaka and Hiroyuki Okazaki and Toshinori Ozaki and Yoshihiko Takano and Jung‐Fu Lin and Hidenori Fujita and Tomoko Kagayama and Katsuya Shimizu and Nozomu Hiraoka and Hirofumi Ishii and Y. F. Liao and K-D. Tsuei and Jun′ichiro Mizuki},
  journal={Scientific Reports},
Pressure dependence of the electronic and crystal structures of KxFe2−ySe2, which has pressure-induced two superconducting domes of SC I and SC II, was investigated by x-ray emission spectroscopy and diffraction. X-ray diffraction data show that compressibility along the c-axis changes around 12 GPa, where a new superconducting phase of SC II appears. This suggests a possible tetragonal to collapsed tetragonal phase transition. X-ray emission spectroscopy data also shows the change in the… 
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