Electrical Properties of Yb-Doped BaTiO3

The equilibrium electrical conductivity of Yb-doped BaTiO3 was studied as a function of oxygen partial pressure P(O-2) and Yb content The conductivity minimum shifted to lower oxygen partial pressure as the Yb content increased XRD analysis revealed that the solid solution of Ba(Ti1-xYbx)O3-x/2 was formed without any extra phases (x <= 5 mol %). The tetragonality of Ba(Ti1-xYbx)O3-x/2 decreased with increasing Yb content and completely switched to a cubic structure at >= 3 mol%. Lattice constants of Ba(Ti1-xYbx)O3-x/2 increase with increasing Yb content The Curie point (T-c) shifted to lower temperatures with increasing Yb content. Dielectric constants rear the Curie temperature (T-c) were markedly suppressed in the specimens with >= 3 mol% Yb, where the crystal structure was confirmed to be cubic (C) 2009 The Japan Society of Applied Physics