Regular Article

Optimizing structure and electrical properties of high-Curie temperature PMN-PHT piezoelectric ceramics via tailoring sintering process

¹ School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, P.R. China
² School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
³ Key Laboratory of Inorganic Function Material and Device, Chinese Academy of Sciences, Shanghai 201800, P.R. China

^a e-mail: fangbj@cczu.edu.cn
^b e-mail: dingjn@cczu.edu.cn
^c e-mail: hsluo@mail.sic.ac.cn

Received: 24 January 2016
Revised: 17 April 2016
Accepted: 22 April 2016
Published online: 3 June 2016

Abstract

Pseudo-ternary high-Curie temperature 0.15Pb(Mg_1/3Nb_2/3)O₃-0.4PbHfO₃-0.45PbTiO₃ (PMN-PHT) piezoelectric ceramics were prepared by the conventional ceramic processing via the columbite precursor method. The influences of sintering temperature and sintering time on structure and electrical properties of the PMN-PHT ceramics were investigated in order to tailor their performance further. The sintered PMN-PHT ceramics exhibit pure perovskite structure with composition locating at the rhombohedral side around the morphotropic phase boundary (MPB) of the PMN-PHT system. The PMN-PHT ceramics sintered at 1260 °C for 2 h exhibit the best dielectric, ferroelectric and piezoelectric properties. The high piezoelectric response of the PMN-PHT ceramics is considered as relating to the MPB effect and their dense microstructure obtained via tailoring sintering conditions. The sintered PMN-PHT ceramics exhibit good thermal stability of piezoelectricity and ferroelectricity within the common usage temperatures, indicating that such ceramics are promising candidates for piezoelectric devices at elevated temperatures.