Enhanced Piezoelectric Properties of Tetragonal (Bi 1/2 K 1/2 )TiO 3 Lead‐Free Ceramics by Substitution of Pure Bi‐Based Bi(Mg 2/3 Nb 1/3 )O 3

• Published in: Journal of the American Ceramic Society Vol. 98; no. 1; pp. 104 - 108
• Main Authors: Pan, Zhao, Wang, Qi, Chen, Jun, Liu, Chuang, Fan, Longlong, Liu, Laijun, Fang, Liang, Xing, Xianran
• Format: Journal Article
• Language: English
• Published: United States American Ceramic Society 01.01.2015
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.13255

Crystal structure, piezoelectric, and dielectric properties were investigated in the new lead‐free BKT‐based piezoelectric ceramics of (1− x )( Bi 1/2 K 1/2 ) TiO 3 ‐ x Bi ( Mg 2/3 Nb 1/3 ) O 3 . The morphotropic phase boundary (MPB) of the system between tetragonal and rhombohedral phases lies near the composition of x  =   0.02. The optimal piezoelectric property of small‐signal d 33 is much enhanced to be 96 pC/N ( x  =   0.01), which is higher than any other BKT‐based compositions. By the introduction of Bi ( Mg 2/3 Nb 1/3 ) O 3 , the ceramics exhibit a lower coercive field E C . In addition, a relaxor‐like behavior with a frequency‐dependent Curie temperature T m is observed, and high Curie temperature T m around 380°C is obtained in the investigated system. This study suggests that the piezoelectric properties of BKT can be significantly improved by the means of Bi ( Mg 2/3 Nb 1/3 ) O 3 substitution.