Abstract
We report a systematic study of the resistivity and magnetic susceptibility of pure , the original Mott-Hubbard system at half filling, for pressures 0≤P≤25 kbar and temperatures 0.35≤T≤300 K. We also study ( under pressure in order to elucidate the role of disorder on a metal-insulator transition in the highly correlated limit. Despite the low level of doping, we find that the two systems are very different. We observe a conventional collapsing of the Mott-Hubbard gap only for stoichiometric ; the Ti disorder stabilizes the long-range antiferromagnetic order and a magnetic Slater gap. Moreover, we discover different P-T phase diagrams for the two systems, with a decoupling of the charge and spin degrees of freedom at the approach to the T=0, pressure-driven metal-insulator transition in pure .
- Received 29 November 1993
DOI:https://doi.org/10.1103/PhysRevB.49.7898
©1994 American Physical Society