Superconductivity in the Electron-Doped Chevrel Phase Compound Mo₆S_6.8Te_1.2

Chevrel-phase superconducting compounds AMo₆Q₈ (A = Pb, Mg, etc. and Q = S, Se, Te) have attracted much attention due to their ultrahigh upper critical magnetic fields (H_c2). However, the binary compounds Mo₆S₈ and Mo₆Te₈ show no superconducting properties above 2 K. In this work, the new Chevrel-phase pseudobinary compound Mo₆S_6.8Te_1.2 with a superconducting transition temperature (T_c) of 3.6 K was successfully synthesized by a two-step process. A detailed investigation implies that the superconductivity in Mo₆S_6.8Te_1.2 may derive from the increased electronic density near the Fermi level in comparison to Mo₆S₈. Our work provides a feasible scheme to search for new superconducting compounds.