Polar relaxation mode in pure and iron-doped barium titanate

A dielectric relaxation peak is reported in ${\mathrm{BaTiO}}_3$ and in ${\mathrm{BaTi}}_{1\mathrm{-}\mathrm{x}}$${\mathrm{Fe}}_{\mathrm{x}}$${\mathrm{O}}_3$. It is nearly monodispersive, centered in the ${10}^8$-Hz range, and slowest at the transition temperature $T_c$≃413 K from the cubic to the tetragonal phase. Iron doping lowers $T_c$ and slows down this relaxation mode.