Electronic transport properties of stuffed compositions of ferromagnetic copper chromium telluride: Cu1+xCr2Te4 (x=0-1)

We present here a detailed study of electronic transport properties of the metallic-ferromagnetic compounds Cu1+xCr2Te4, having excess Cu atoms with x=0-1, from 2 to 400 K. The stuffing of the copper atoms in the parent structure reduces the ferromagnetic ordering temperature T-C from 325 to 156 K, while for the entire range the dependence of the electrical resistance and the thermopower with temperature and the anomalies in them on the magnetic ordering remain similar. All the compounds show a magnon-drag contribution in thermopower as a positive maximum around T-C/3, and a T-2 - dependence of resistivity at low temperatures. The increasing effects of the short range magnetic ordering in the paramagnetic resistivity are seen with the increase in the stuffing of atoms in these compounds. The transport properties are explained by the current carriers - the holes in a wide energy band dominated by the p-state of Te-atoms, which are scattered by the spindisorder in the paramagnetic phase and from the magnons in the ferromagnetic phase. (C) 2011 Elsevier B.V. All rights reserved.