ABSTRACTPiezoelectric thin films are useful for application in microelectromechanical devices. A series of sol-gel derived PZT (lead zirconate titanate) thin films with various Zr/Ti ratios were prepared on platinized substrates. These films were fired to 650C - 700C to crystallize them into single-phase perovskite films, and their piezoelectric properties were measured using optical lever-based instrumentation. Large d33 piezoelectric coefficients up to 400 pm/V were obtained at the morphotropic phase boundary (PZT 53/47), making such films attractive in applications such as thin film transducers, microcanti levers and surface acoustic wave devices.