Improved piezoelectric performance via orientation regulation in novel BNT-BT-SBT thin film

Abstract

Lead-free piezoelectric thin films are urgently needed in microelectronic and microelectromechanical systems. In this work, (1-x)(0.94Bi0.5Na0.5TiO3-0.06BaTiO3)-x(Sr0.7Bi0.2□0.1)TiO3 (abbreviated as BNT-BT-xSBT) piezoelectric thin films were prepared successfully. The optimal piezoelectric performance can be achieved when x = 0.02 at morphotropic phase boundary (MPB). Further, to explore the impacts of orientation control on the properties of thin films, (100), (110), and (111)-oriented BNT-BT-0.02SBT thin films were prepared on Nb-SrTiO3 single crystal. The (110) preferred orientation thin film can achieve a high inverse piezoelectric coefficient (d33*) of 170 pm/V, which has a great improvement contrasted with non-oriented films. From the perspective of engineering domain configuration, the high d33* of (110)-oriented thin film can be characterized that the ferroelectric domain can get a complete flip in the direction of non-easily polarized axes. In short, orientation regulation is of great importance in improving the piezoelectric properties of thin films and has important applications in microelectronic sensing.