Pressure effect on superconductivity in FeSe0.5Te0.5

Sergii I. Shylin; Vadim Ksenofontov; Pavel G. Naumov; Sergey A. Medvedev; Vladimir Tsurkan; Joachim Deisenhofer; Alois Loidl; Leslie M. Schoop; Taras Palasyuk; Gerhard Wortmann; Claudia Felser

doi:10.1002/pssb.201600161

arXiv · 1609.06179

Pressure effect on superconductivity in FeSe0.5Te0.5

Sergii I. Shylin·Vadim Ksenofontov·Pavel G. Naumov·Sergey A. Medvedev·Vladimir Tsurkan·Joachim Deisenhofer·Alois Loidl·Leslie M. Schoop·Taras Palasyuk·Gerhard Wortmann·Claudia Felser

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Abstract

Due to the simple layered structure, isostructural FeSe and FeSe0.5Te0.5 are clue compounds for understanding the principal mechanisms of superconductivity in the family of Fe-based superconductors. High-pressure magnetic, structural and Mössbauer studies have been performed on single-crystalline samples of superconducting FeSe0.5Te0.5 with Tc = 13.5 K. Susceptibility data have revealed a strong increase of Tc up to 19.5 K for pressures up to 1.3 GPa, followed by a plateau in the Tc(p) dependence up to 5.0 GPa. Further pressure increase leads to a disappearance of the superconducting state around 7.0 GPa. X-ray diffraction and Mössbauer studies explain this fact by a tetragonal-to-hexagonal structural phase transition. Mössbauer parameters of the non-superconducting high-pressure phase indicate less covalency of Fe-Se bonds. Based on structural and susceptibility data we conclude about a common character of Tc(p) diagrams for both FeSe and FeSe0.5Te0.5 superconductors.

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Sergii I. Shylin, Vadim Ksenofontov, Pavel G. Naumov, Sergey A. Medvedev, Vladimir Tsurkan, Joachim Deisenhofer, Alois Loidl, Leslie M. Schoop, Taras Palasyuk, Gerhard Wortmann, Claudia Felser. 2016-09-20. Pressure effect on superconductivity in FeSe0.5Te0.5. https://doi.org/10.1002/pssb.201600161

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