High-Pressure Nuclear Resonance Study of the Metal-Insulator Transition ofV2O3

Abstract

${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$ nuclear magnetic resonance (NMR) has been observed in metallic ${\mathrm{V}}_2$ ${\mathrm{O}}_3$ at pressures up to 65 kbar at 4.2 °K. Pressures greater than 26 kbar suppress the metal-to-antiferromagnetic insulator transition, leaving ${\mathrm{V}}_2$ ${\mathrm{O}}_3$ a metal at 4.2 °K. ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$ NMR shows that the metallic phase, unlike the insulating phase, does not order magnetically down to 4.2 °K. The measurements are the highest-pressure resonance measurements which have been reported in the He temperature range. Knight shifts and relaxation times were measured, the Knight shift having an anomalously strong dependence on volume. The relaxation time allows an upper limit of ${10}^{-13\mathrm{}}$ sec to be placed on the spin fluctuation lifetime of the $d$ electrons.