Rare-Earth Magnetic Isolation and Superconductivity of the Chevrel-Phase Compounds

Abstract

Results of ab initio self-consistent linear muffin-tin orbital energy-band studies for Eu${\mathrm{Mo}}_6$ ${\mathrm{S}}_8$, Gd${\mathrm{Mo}}_6$ ${\mathrm{S}}_8$, Sn${\mathrm{Mo}}_6$ ${\mathrm{S}}_8$, and Sn${\mathrm{Mo}}_6$ ${\mathrm{Se}}_8$ including all electrons in all 15 atoms/unit cell are reported. The large charge transfer from both the Eu, Gd, and Sn sites and from the Mo sites to the chalcogens is shown to be the driving mechanism with which to explain their unusual magnetic and superconducting properties.