Electromechanical properties of calcium bismuth titanate films: A potential candidate for lead-free thin-film piezoelectrics

Abstract

Ca Bi 4 Ti 4 O 15 (CBTi144) thin films were evaluated for use as lead-free thin-film piezoelectrics in microelectromechanical systems. The films were grown by the polymeric precursor method on (100)Pt∕Ti∕SiO2∕Si substrates. The a∕b-axis orientation of the ferroelectric film is considered to be associated with the preferred orientation of the Pt bottom electrode. The Pr and Ec were 14μC∕cm2 and 64kV∕cm, respectively, for a maximum applied field of 400kV∕cm. The domain structure was investigated by piezoresponse force microscopy. The film has a piezoelectric coefficient, d33, equal to 60pm∕V and a current density of 0.7mA∕cm2.