Ab initio study on magnetism suppression, anharmonicity, rattling mode, and superconductivity in Sc6MTe2 (M=Fe,Co,Ni)
Journal
Physical Review B
Journal Volume
110
Journal Issue
10
Start Page
104505
ISSN
2469-9950
2469-9969
Date Issued
2024-09-04
Author(s)
Abstract
We perform a systematic ab initio study on phonon-mediated superconductivity in the transition-metal-based superconductors Sc6MTe2(M=Fe,Co,Ni). Firstly, our charge analysis reveals significant electron transfer from Sc to M because of the substantial difference in the electronegativity, filling the 3d orbitals of M and suppressing magnetic instability. Secondly, we show that Sc6FeTe2 exhibits strong lattice anharmonicity. Moreover, for M=Fe and Co, we find low-frequency soft phonon bands of M, which can be interpreted as "rattling phonons"in the framework formed by Sc. While not observed in the case of M=Ni, the rattling phonons give rise to a prominent peak or plateau in the Eliashberg spectral function and enhance the pairing instability. By reproducing the experimental trend of superconducting transition temperatures, our study underscores the potential of designing phonon-mediated superconductors by strategically combining nonsuperconducting and magnetic transition-metal elements.
Publisher
American Physical Society (APS)
Type
journal article