Measurement of piezoelectric coefficients of lead zirconate titanate thin films by strain-monitoring pneumatic loading method

A method to simultaneously measure the longitudinal (d(33)) and transverse (d(31)) piezoelectric coefficients of a lead zirconate titanate (PZT) thin film was developed. This system was based on the pneumatic loading method but was modified to monitor the radial strain when a pressurized gas was introduced into the chamber. The results of the bulk piezoelectric material measured by this system coincided with that measured by both the Berlincourt method and the resonance method. The effective d(33) and the real d(31) of the PZT thin film fabricated by the sol-gel multiple coating method, and poled at 300 kV/cm were 125 and -60 pC/N, respectively. The real d(33) estimated upon considering the constraints by the silicon substrate was 180 pC/N. (C) 2002 American Institute of Physics.