High temperature 0.63BiFeO3-0.37BaTiO3 based ceramics with large electromechanical properties by simple A-site K+ doping

Abstract

Designing high temperature piezoelectric ceramics with large electromechanical properties is key to the actuators application in harsh environment. BiFeO3-BaTiO3 based piezoelectric ceramics are the promising candidates due to their high electromechanical properties and high Curie temperature. Here, the simple A-site single K+ doped 0.63Bi1−xKxFeO3-0.37BaTiO3 (abbreviated as 0.63B1−xKxF-0.37BT) ceramics with positive temperature dependent electromechanical properties were fabricated via conventional solid phase method. The electromechanical properties in the 0.63B1−xKxF-0.37BT ceramics are closely related to the content of K+ doping. The excellent electromechanical properties of S= 0.26% and d33*=861 pm/V under low electric field of 30 kV/cm at 105 ℃ are achieved in the 0.63B0.9975K0.0025F-0.37BT ceramic, which is conducive to their application at high temperature. Combined with the microstructure and PFM, the optimized electromechanical properties in 0.63B0.9975K0.0025F-0.37BT ceramic are mainly due to more nanodomains switching facilitated by the large grain size and local structural heterogeneity. The site engineering of A-site single ion doping is an efficient and simple strategy for BF-BT based piezoelectric ceramics to achieving excellent electromechanical properties under low electric field at high temperature.