Acoustical study of the phase trawsition in SrTiO3 surface layers

Velocity and attenuation of surface and bulk acoustic waves were measured in SrTiO₃ in the phase transition region. The model of surface layer with thickness which does not vary with temperature is proposed. The layer transforms into the low-symmetry phase at temperature higher than the Curie temperature of the bulk. Effect of surface polishing on phase transition in the layer was observed.