Dielectric polarization in xPbZn_(1/3)Nb_(2/3)O_3-(1-x)PbSc_(1/2)Nb_(1/2)O_3 ferroelectric solid solutions

摘要

Manifestation of relaxor properties in the xPbZn_(1/3)Nb_(2/3)O_3-(1-x)PbSc_(1/2)Nb_(1/2)O_3 ceramic solid solution system, similar to those observed in lead magnesium niobates, are reported. Dependence of the effective dielectric permittivity and dielectric loss on the temperature at frequencies of 0.1-10 Hz and different measuring field amplitudes E_0 are examined in ceramic samples of 0.05PbZn_(1/3)Nb_(2/3)O_3-0.95PbSc_(1/2)Nb_(1/2)O_3. It is demonstrated that the temperatute at which the dielectric permittivity has a maximum, T_m, decreases with the increase of E_0. The dependence of T_m on the frequency in both strong and weak fields is shown to follow the Vogel-Fulcher law, with Vogel-Fulcher temperature decreasing with the increase of E_0. The results of the dielectric studies in the xPbZn_(1/3)Nb_(2/3)O_3-(1-x)PbSc_(1/2)Nb_(1/2)O_3 system are discussed in terms of the transition from the paraelectric to ferroelectric phase through the relaxor and glass states.