Phase transitions in SrTiO3-based solid solutions

Phase transitions in solid solutions of strontium titanate with titanates of the divalent metals Pb, Ba, and Ca are considered. It is shown that the critical concentration x _c in the well-known expression relating the transition temperature to the polar state in SrTiO₃ with the concentration x of divalent metals, T _c=A(x−x _c)^1/2, is practically the same for all impurities. For large values of x, the ferroelectric transition temperature T _c depends linearly on x. The volume and impurity contributions to the T _c(x) relation are determined for this concentration range. Fiz. Tverd. Tela (St. Petersburg) 39, 1645–1651 (September 1997)