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arXiv · 0904.1816

Superconducting and normal phases of FeSe single crystals at high pressure

D Braithwaite·B Salce·G Lapertot·F Bourdarot·C Marin·D Aoki·M Hanfland
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Abstract

We report on the synthesis of superconducting single crystals of FeSe, and their characterization by X-ray diffraction, magnetization and resistivity. We have performed ac susceptibility measurements under high pressure in a hydrostatic liquid argon medium up to 14 GPa and we find that TC increases up to 33-36 K in all samples, but with slightly different pressure dependences on different samples. Above 12 GPa no traces of superconductivity are found in any sample. We have also performed a room temperature high pressure X-ray diffraction study up to 12 GPa on a powder sample, and we find that between 8.5 GPa and 12 GPa, the tetragonal PbO structure undergoes a structural transition to a hexagonal structure. This transition results in a volume decrease of about 16%, and is accompanied by the appearance of an intermediate, probably orthorhombic phase.

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D Braithwaite, B Salce, G Lapertot, F Bourdarot, C Marin, D Aoki, M Hanfland. 2009-05-12. Superconducting and normal phases of FeSe single crystals at high pressure. https://doi.org/10.1088/0953-8984%2F21%2F23%2F232202

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