Autor: |
Cheung, Y. W., Zhang, J. Z., Zhu, J. Y., Yu, W. C., Hu, Y. J., Wang, D. G., Otomo, Yuka, Iwasa, Kazuaki, Kaneko, Koji, Imai, Masaki, Kanagawa, Hibiki, Yoshimura, Kazuyoshi, Goh, S. K. |
Jazyk: |
angličtina |
Rok vydání: |
2016 |
Zdroj: |
Physical Review B. 93(24):241112_1-241112_5 |
ISSN: |
2469-9950 |
Popis: |
The quasi-skutterudite superconductor La$_3$Co$_4$Sn$_{13}$ undergoes a phase transition at $T^{*}$ = 152 K. By measuring the temperature dependence of heat capacity, electrical resistivity, and the superlattice reflection intensity using X-ray, we explore the character of the phase transition at $T^{*}$. Our lattice dynamic calculations found imaginary phonon frequencies around the $M$ point, when the high temperature structure is used in the calculations, indicating that the structure is unstable at the zero temperature limit. The combined experimental and computational results establish that $T^{*}$ is associated with a second-order structural transition with $q$ = (0.5, 0.5, 0) (or the $M$ point). Further electronic band structure calculations reveal Fermi surface sheets with low-curvature segments, which allow us to draw qualitative comparison with both Sr$_3$Ir$_4$Sn$_{13}$ and Sr$_3$Rh$_4$Sn$_{13}$ in which similar physics has been discussed recently. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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