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Abstract: The influence of the prehistory on the electrical properties of layered ferroelectrics is investigated. It is established that the heating of short-circuited samples of the nonpolarized ceramic material Na0.5Bi8.5Ti2Nb4O27 leads to the appearance of maxima of the current at temperatures below the Curie point only in the case of preliminary ageing of the samples.

Abstract: A dielectric response of the Pb(Mg1/3Nb2/3)O3 ferroelectric ceramics with impurity of 2 wt % Li has been studied. The phase transition has been found to exhibit a relaxor character, as is the case in PMN without Li. However, unlike pure PMN, the dielectric response dispersion in PMN + 2 wt % Li2O has been described by the Cole-Cole equation at temperatures below the temperature of the low-frequency maximum of the permittivity. An analysis of the dispersion parameters in a wide temperature range has demonstrated that it can be due to the relaxation of domain walls in PMN + 2 wt % Li2O that appear most likely because of the existence of anomalously coarse grains in PMN + 2 wt % Li2O.