Magnetic properties of (V1-xCrx)(2)O-3

The magnetic susceptibility of the (V1-xCrx)(2)O-3 system (0 <= x <= 1) has been studied over the temperature range 4.2-1000 degrees K. For 0 <= x < 0.035, the susceptibility data clearly indicate both the high-temperature transition from a paramagnetic insulating to a paramagnetic metallic state with decreasing temperature and the sharp low-temperature transition from the paramagnetic metallic phase to the insulating antiferromagnetic phase. Separation of the total susceptibility into a temperature-independent Van Vleck term and a temperature-dependent term chi(d) yields Curie-Weiss behavior for chi(d). As x increases from 0 to 0.035, the extrapolated paramagnetic Curie temperature of the insulating high-temperature phase decreases from 600 to 350 degrees K and the effective moments from 2.96 mu(B) to 2.30 mu(B) per magnetic ion. The change from the V2O3-type magnetic structure to the Cr2O3 type occurs in the region 0.21 <= x <= 0.45. The magnetic susceptibility data are consistent with the picture developed for pure and Cr-doped V2O3 on the basis of resistivity and x-ray investigations at atmospheric and elevated pressures.