Non-Stoichiometric Effect in (K,Na)NbO3-Based Perovskite Ceramics

作者：Cho Jeong Ho^*; Yeom Na Ri; Kwon So Jung; Jeong Young Hun; Lee Young Jin; Chun Myoung Pyo; Nam Joong Hee; Paik Jong Hoo; Kim Byung Ik

来源：Japanese Journal of Applied Physics, 2012, 51(9): 09MD09.

DOI：10.1143/JJAP.51.09MD09

We prepared Li-0.04(K0.5Na0.5)(x)(NbySb0.06)O-3 ceramics using the conventional solid-state sintering method and investigated the non-stoichiometric effect on sintering behavior and electrical properties in these material systems. The deficiency of B-site ions gave rise to poor densities, while the densification was improved by adding excess Nb2O5. As the vacancy concentration in the A-site of the perovskite structure increased, the diffuse phase transition was enhanced and the transition temperature (To-t) was lowered. Furthermore, high deficiency in the A-site with x = 0.90 and y = 0.98 promoted a second phase formation. An increase of alkali cation vacancies led to large remnant polarization and enhanced a pinched hysteresis loop, while the remnant polarization decreased due to a second phase formation. The electro-mechanical coupling factors were significantly influenced by density and second phase formation, not non-stoichiometry, while dielectric constants were influenced by non-stoichiometry, not second phase formation.

• 出版日期2012-9