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arXiv · 1906.04894

Close correlation between superconducting transition temperatures and carrier densities in Te- and S-substituted FeSe thin films

Fuyuki Nabeshima·Tomoya Ishikawa·Naoki Shikama·Atsutaka Maeda
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Abstract

We comparatively investigated the transport properties for S- and Te-substituted FeSe thin films under magnetic fields to clarify the origin of the contrasting behavior of the superconducting transition temperature in S and Te substitution. A classical two carrier analysis revealed that the carrier densities of the films increased with increasing Te content, while no significant change was observed for the S-substitution. This composition dependence of the carrier density well corresponds to the $T_{\mathrm c}$ behavior. The clear correlation between $T_{\mathrm c}$ and the carrier densities suggests that the structural transition affects the electronic structure in a different manner between Fe(Se,S) and Fe(Se,Te) and that this fact is the direct cause of the difference in the $T_{\mathrm c}$ behaviors at the end point of the structural transition.

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Fuyuki Nabeshima, Tomoya Ishikawa, Naoki Shikama, Atsutaka Maeda. 2019-06-12. Close correlation between superconducting transition temperatures and carrier densities in Te- and S-substituted FeSe thin films. https://doi.org/10.1103/physrevb.101.184517

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