The relations of sintering conditions and microstructures of [Bi_0.5(Na_1‐x‐yK_xLi_y)_0.5]TiO₃ piezoelectric ceramics

Abstract

Abstract Bismuth sodium titanate (abbreviated as BNT) based solid solution, [Bi 0.5 (Na 1‐x‐y K x Li y ) 0.5 ]TiO 3 (0 < x + y < 1) ceramics, was invented in our group. These ceramics, which are considered as new candidates for lead‐free piezoelectric materials, were prepared by conventional ceramic sintering technique. The results of X‐ray diffraction show that the ceramics possess a single perovskite phase. The relations of the sintering conditions and the microstructures of the ceramics were studied. It was found that the optimized sintering condition is at 1100‐1150 °C for 2‐3 h, the grains of the ceramics have very regular shape, and the grain size of the ceramics is in the range of 1.3‐2.2 μm. These ceramics with the compositions of high amount of K + and low amount of Li + have relatively large piezoelectric charge constant ( d 33 ), and can be put into practical applications. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)