Electrical and thermal transport measurements on semimetallic rare-earth sesquisulfides

Measured values of ρ, RH, α, and κ are reported on single-crystal samples of Nd₂{S}₃$, ${Gd}₂S₃, and Dy₂{S}₃$ containing excess rare earth in the defect lattice structure. Measurements cover the temperature range between roughly 7 and 1000 K, and an excess rare-earth composition range between 0.1 and 0.7 wt%. Data can be interpreted in terms of the Cutler-Mott model modified for magnetic effects by von Moln\'ar, Holtzberg, Penney, and their associates. Above 100 K, alloy scattering appears dominant. At lower temperatures the transport mechanism favors a hopping process for localized electrons in a magnetically ordered lattice.