Synthesis, Microstructure, Dielectric and Ferroelectric Properties of (Na,Bi,K)TiO 3 Ceramics

Single-phase ceramic samples with the perovskite structure [(Na0.5Bi0.5)1 – xKx] TiO3 (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06) are prepared by the method of solid-state synthesis and their structure, microstructure and dielectric and ferroelectric properties are studied. An increase in the unit-cell parameters of the perovskite lattice as a result of an increase in the K-cation content in accordance with the ratio of the radii of cations in the A sublattice of the perovskite structure is proved. The method of second-harmonic generation confirms that the introduction of potassium cations in the A positions of the perovskite lattice promotes enhancement of the ferroelectric properties of the studied samples. Dielectric-relaxation effects are revealed, which indicate the presence of vacancies in the oxygen sublattice.