The effects of incorporating La3+ ions into Na1/2Bi1/2TiO3 on the microstructure and sintering characteristics were studied. As the content of incorporated La3+ was increased in [(Na0.5Bi0.5)1-1.5x V0.5xLax]TiO3, the sintered density reached a maximum at x = 0.05 and the grain size decreased as La ions increased from x = 0 to 0.05. In (Na0.5Bi0.5-xLax)TiO3, the incorporated La ions decreased the bulk density and increased the grain size. The effect of various La incorporation methods upon the microstructural changes suggested that LaA•-VA' pairs played a critical role in suppressing fast grain boundary movement and enhancing the densification of [(Na0.5Bi0.5)1-1.5x V0.5xLax]TiO3 ceramics. Additions of La also changed the electrical properties of Na1/2Bi1/2TiO3.

The Role of Cation Vacancies on Microstructure and Piezoelectricity of Lanthanum-Substituted (Na1/2Bi1/2)TiO3 Ceramics. J.Y.Yi, J.K.Lee, K.S.Hong: Japanese Journal of Applied Physics, 2004, 43[9A], 6188-92