Normal-state electrical resistivity of Chevrel-phase superconductors of the type Cu_1.8Mo₆S_8-ySe_y, 0⩽y⩽8

Abstract

Normal-state electrical resistivity data from 12-300K on Chevrel-phase superconductors of the type Cu1.8Mo6S8-ySey, 0<or=y<or=8, are reported. The temperature dependence of the normal-state resistivity has been analysed on the basis of models proposed for A15 superconductors. It is found that the 'parallel resistor' model based on s-d scattering accounts for the observed variation satisfactorily in most of the compounds, provided the lower limit of the transport theory integral is taken to have a non-zero value obtained by a fit to the experimental data. Physically, this limit corresponds to the minimum energy required for a phonon to scatter an electron from the s band into the d band. The electrical resistivity below 40K could also be interpreted on the basis of interband electron-electron scattering.