Meta–Insulator Phenomena in Strongly Correlated Oxides. The Vacancy-Doped Titanate Perovksites, Nd1−xTiO3 and Sm1−xTiO3

Electrical transport, both resistivity and thermopower, and heat capacity data are reported for two systems of cation vacancy-doped titanate perovskites, Nd1−xTiO3 and Sm1−xTiO3. In the former case the range of x is from 0.33 to 0.00 and for the latter from 0.17 to 0.00. Thus, the nominal carrier concentration, n, can be varied from 0 (x=0.33) to 1.0 (x=0.00) electrons per Ti atom. For the Nd series two distinct metal–insulator transitions …