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 TC 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 TC/3, and a T2 - 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.

► Resistivity and the thermopower of series of Cu1+xCr2Te4x=0–1 from 2to600 K. ► Spin-disorder scattering of conduction electrons in the paramagnetic phase. ► Magnon-drag effects, as a positive maximum at TC/3 in thermopower. ► Short range ordering caused by the frustration effects of the interactions by interstitial atoms. ► Alloy-like structural and electronic properties by the increase in stuffing of the copper atoms.