X-ray study of phase transitions in efrroelectric Na0.5Bi0.5TiO3

Abstract
The temperature dependence of the lattice constant in Na0.5Bi0.5TiO3 single crystal was studied by means of X-ray diffraction. Two structural phase transitions were found in the temperature range 293-920 K: the cubic-to-tetragonal at 793 ± 5 K and the tetragonal-to-rhombohedral at 533 ± 5 K. The dielectric permittivity was measured and a considerable dispersion was observed. The shift of the dielectric permittivity maximums are linear in coordinates 1/T = F(In f).