Single-phase ceramic samples with the perovskite structure [(Na_0.5Bi_0.5)_1 – xK_x] 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.

中文翻译：

---

（Na，Bi，K）TiO 3陶瓷的合成，微结构，介电和铁电性能

采用固态法制备钙钛矿结构[（Na _0.5 Bi _0.5）_{1-  x} K _x ] TiO ₃（x = 0，0.01，0.02，0.03，0.04，0.05，0.06 ）的单相陶瓷样品。研究了其合成，结构，微观结构以及介电和铁电性能。证明了钙钛矿结构的A子晶格中的K-阳离子含量随阳离子半径比的增加而增加了钙钛矿晶格的晶胞参数。次谐波产生的方法证实了钾离子在A中的引入钙钛矿晶格的位置促进了所研究样品的铁电性能的增强。揭示了介电松弛效应，这表明氧亚晶格中存在空位。