A dramatic influence of bias field on pyroelectric response was revealed for ceramics of (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ with x = 0.075, 0.33 and 0.98Pb(Fe_1/2Nb_1/2) O_3–0.02PbTiO₃. Temperature and bias field dependency of the dielectric permittivity and dynamic pyroelectric coefficient have been studied to establish possible relation of the enhanced pyroelectric activity with the E-T phase diagram. In relaxor ceramic composition PMN-0.075 the highest pyroelectric coefficient was achieved at the point having quasi-critical features. These data support an assumption of quasi-critical behavior of the pyroelectric response in relaxor ceramics, in accord with our previous data for relaxor single crystals.

Dielectric, X-ray, pyroelectric and piezoelectric studies of the (1-x)PbFe_1/2Nb_1/2O₃–(x)PbTiO₃ ceramics from the 0 ≤ x ≤ 0.2 range fabricated by solid state synthesis and usual sintering have been carried out. In PbFe_1/2Nb_1/2O₃ and compositions with low Ti content anomalies of dielectric, pyroelectric and piezoelectric parameters, corresponding to the transition between two ferroelectric phases have been observed at 85–90°C. A dramatic effect of bias field on dielectric and pyroelectric responces was revealed.

High-quality ceramics were synthesized on the basis of Bi1 − x A xFeO3 ( A = La, Nd; 0.00 ≤ x≤ 0.20) solid solutions. Their crystal and grain structure, Mössbauer spectra, and other dielectric and...

The reasons for the high electrical conductivity of bismuth ferrite due to its natural composite structure, structural non-stoichiometry, redox processes, and the boundary position in the perovskite family have been considered. It has been shown that it is possible to significantly (2–3 orders of magnitude) reduce the conductivity of BiFeO₃ by introducing large-sized ions of rare-earth elements (REE: La, Pr, Nd, Sm, Eu, Gd with 0.94 ≤ $\overline{R}$ ≤ 1.04 Å) in amounts of up to 10 mol %. An interpretation of the observed effects has been given. A consideration about the appropriateness of taking into account the presented results when developing devices using materials of the BiFeO₃/REE type has been expressed.

The piezodielectric and ferroelastic properties of solid solutions of the multi-component system 0.98(xPbTiO_3−y PbZrO_3−z PbNb_2/3Mg_1/3O₃)-0.02PbGeO₃ are studied in the temperature range of 30–400°C. Abnormalities of the above dependences are revealed, and it is suggested that the observed phenomena are of a physical nature.