Doping- and pressure-induced change of electrical and magnetic properties in the Mott-Hubbard insulator LaTiO3.

A perovskitelike compound LaTiO[sub 3] shows insulating or barely metallic behavior depending on a slight ([le]0.04) deviation of the Ti valence (+3) arising from nonstoichiometry of La and/or oxygen. In order to investigate electronic properties of the specimens in the very vicinity of the Mott insulator-metal phase boundary, we have measured the doping- and pressure-induced effects on the electrical and magnetic properties. The results have indicated a crossover behavior from localized to itinerant nature of the electronic state with increase of the doping level and one-electron bandwidth.