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Electronic phase transition in the Re3Ge7 endohedral cluster compoundстатья
- Авторы: Verchenko V.Yu, Likhanov M.S., Mironov A.V., Shevelkov A.V.
- Журнал: Physical Review B
- Том: 106
- Номер: 19
- Год издания: 2022
- Издательство: American Physical Society
- Местоположение издательства: United States
- DOI: 10.1103/physrevb.106.195203
- Аннотация: Re3Ge7 is a unique electronic material showing low-temperature metal–insulator-like phase transition. Furthermore, bulk superconductivity can be induced in Re3Ge7 by hole doping. Here, we present transport properties, temperature-dependent high-resolution powder x-ray diffraction study, and electronic structure of Re3Ge7 in the vicinity of the electronic phase transition. Electrical resistivity and heat capacity measurements confirm the anomaly at 58.5 K in zero magnetic field. The Seebeck coefficient changes its sign and exhibits a maximum below the transition temperature indicating substantial changes in the electronic structure. Temperature-dependent structural studies confirm the second-order nature of phase transition, where unit cell parameters show abrupt change at the transition temperature. An analysis of interatomic distances indicates that the shrinkage of the unit cell volume is due to the interatomic changes taking place in the second coordination sphere of Re atoms. Electronic structure calculations reveal strong 5d−4p hybridization of valence orbitals near the Fermi level, which is situated between two deep pseudogaps of the density of states. The transition to the semiconducting state is accompanied by the opening of a band gap at the Fermi level right above the narrow pocket of hybridized states.
- Добавил в систему: Лиханов Максим