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

Ca Bi4 Ti4 O15 (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) PtTiSi O2 Si substrates. The ab -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 14 μC cm2 and 64 kVcm, respectively, for a maximum applied field of 400 kVcm. The domain structure was investigated by piezoresponse force microscopy. The film has a piezoelectric coefficient, d33, equal to 60 pmV and a current density of 0.7 mA cm2. © 2006 American Institute of Physics.