Abrupt structural transition in V₂O₃ revealed by pair distribution function analysis

V₂O₃ is an important material for the study of Mott insulators and other strongly correlated electron systems. Despite decades of research, a complete understanding of the metal-insulator transition in V₂O₃ has not been conclusively established. Here, we present comprehensive atomic and magnetic pair distribution function (PDF) analyses of V₂O₃ using both x-ray and neutron total scattering measurements, shedding new light on the mechanism of the transition from the point of view of short-range structural and magnetic correlations on both sides of the transition. We observe an abrupt structural transition with no hint of short-range monoclinic distortions above the transition temperature. This lack of structural fluctuations above the transition contrasts with the known presence of magnetic fluctuations in the high-temperature state, suggesting that the lattice degree of freedom plays a secondary role behind the spin degree of freedom in the transition mechanism.