The study of the movement of the paraelectric-ferroelectric interphase boun
dary in (Ba,Sr)TiO3 with concentration change is provided in the framework
of the mean-field theory. The analytical solution for the parameters of mot
ion of the interphase boundary is applied to the calculations of the splitt
ing of domain walls in (Ba,Sr)TiO3 for different concentrations of Sr. The
calculations are based on the experimental data for the Curie-Weiss constan
t and for the parameters of the Landau-Ginzburg expression for the free ene
rgy. (C) 1998 Elsevier Science S.A. All rights reserved.