Magnetic Properties of(V1−xCrx)2O3

The magnetic susceptibility of the ${\left({\mathrm{V}}_{1-x}{\mathrm{Cr}}_x\right)}_2{\mathrm{O}}_3$ system ($0\le x\le 1$) has been studied over the temperature range 4.2-1000 °K. For $0\le x<\mathrm{}0.035\mathrm{}$, 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 °K and the effective moments from $2.96{\mu }_B$ to $2.30{\mu }_B$ per magnetic ion. The change from the ${\mathrm{V}}_2$ ${\mathrm{O}}_3$-type magnetic structure to the ${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$ type occurs in the region $0.21\le x\le 0.45$. The magnetic susceptibility data are consistent with the picture developed for pure and Cr-doped ${\mathrm{V}}_2$ ${\mathrm{O}}_3$ on the basis of resistivity and x-ray investigations at atmospheric and elevated pressures.