Electrical resistivity of Gd and La monochalcogenides

The Gd monochalcogenides form a very interesting system of ionic and antiferromagnetic metals (40Kstoichiometry without changing crystal symmetry or phase purity. The paramagnetic Curie temperature and the carrier concentration can be varied drastically with stoichiometry, resulting in a spectacular change in color [1,2,3]. In this paper was present electrical resistivity data of GdS, GdSe, GdTe and LaS, LaSe, LaTe single crystals, which have been measured between 4 K and 300 K by an ac four probe technique for samples with varying stoichiometry. The La monochalcogenides have been chosen as the nonmagnetic counter‐parts to investigate the influence of alone the stoichiometry variation on the resistivity. It is observed that in the Gd chalcogenides a kink in the resistivity at TN for excess metal develops into a maximum at TN for stoichiometric samples. For these compounds the Langer‐Fisher theory of spin disorder scattering sufficiently explains the observed resu...