We have synthesized AgSn1-xBixSe2 polycrystalline samples to investigate the effect of partial substitution of mixed-valence Sn by Bi3+ to the superconductivity of the valence-skip superconductor AgSnSe2. The Bi-substituted AgSn1-xBixSe2 were obtained up to x = 0.2, but an insulating phase Ag2SnBi2Se5 with a NaCl-type structure showed up above x = 0.3. The superconducting transition temperature increased from 4.5 K (x = 0) to 5.0 K (x = 0.1) by Bi substitution. The enhancement of superconductivity by the suppression of the valence-skip states of Sn suggests that the valence-skip states of Sn are not positively linked to the pairing mechanisms of superconductivity in the AgSnSe2 system.
@article{arxiv.1702.01196,
title = {Bi Substitution Effects on Superconductivity of Valence-Skip superconductor AgSnSe2},
author = {Yudai Hijikata and Atsuhiro Nishida and Kohei Nagasaka and Osuke Miura and Akira Miura and Chikako Moriyoshi and Yoshihiro Kuroiwa and Yoshikazu Mizuguchi},
journal= {arXiv preprint arXiv:1702.01196},
year = {2017}
}
Comments
18 pages, 9 figures and 2 tables including Supplemental Materials