DIELECTRIC PROPERTIES OF Ba0.8Sr0.2TiO3 FERROELECTRIC FILMS IN AN ALTERNATING ELECTRIC FIELD

Thin films of Ba0.8Sr0.2TiO3 were obtained by high-frequency sputtering on (100)p-Si substrates. Results of studies of frequency and temperature dependences of real and imaginary parts of dielectric permittivity of Ba0.8Sr0.2TiO3 ferroelectric film on alternating electric current are presented. It has been found that the polarization process has an activation character, the real and imaginary parts of the dielectric permeability decrease with increasing frequency, and the decrease rate is much higher at relatively low frequencies than at high frequencies. The relaxation time has been calculated and this crystal has been found to have an electron polarization mechanism due to thermal motion.