Metal—antiferromagnetic-insulator transition inV2O3alloys

Abstract

Electrical resistivity measurements are reported for a variety of ${\left({\mathrm{V}}_{1-x}{\mathrm{Ti}}_x\right)}_2{\mathrm{O}}_3$ and ${\mathrm{V}}_{2(1-y)\mathrm{}}{\mathrm{O}}_3$ systems, with $0\le x<\mathrm{}0.06\mathrm{}$ and $0\le y<\mathrm{}0.01\mathrm{}$, in the range 20-300 K. The metal—antiferromagnetic-insulator transition temperature $T_N$ diminishes steadily with increasing $x$ and $y$ and drops abruptly to zero at a critical concentration. The size of the discontinuity in electrical resistivity at $T_N$ diminishes with $T_N$ for the Ti-alloy system; for nonstoichiometric ${\mathrm{V}}_2$ ${\mathrm{O}}_3$ it passes through a minimum and then rises significantly. These features can be rationalized almost quantitatively by assuming that acoustic lattice and ionized-impurity scattering processes govern the mobility of the itinerant charge carriers in the ${\left({\mathrm{V}}_{1-x}{\mathrm{Ti}}_x\right)}_2{\mathrm{O}}_3$ and ${\mathrm{V}}_{2(1-y)\mathrm{}}{\mathrm{O}}_3$ systems, respectively.