Measurement of thin film piezoelectric constants using x-ray diffraction technique

Abstract

A new method to measure the piezoelectric constants of d33 f and d31 f of thin films using x-ray diffraction (XRD) is proposed. Piezoelectric constant d33 f is calculated from the measurement of change in out-of-plane lattice spacing of the piezoelectric films while piezoelectric constant d31 f is obtained from the change in the slope of dψ versus sin 2 ψ curves before and after applying an electric field over the film. This method improves the accuracy by directly measuring the strains in the films induced by the externally applied electric field instead of the surface displacement that could easily be interfered with by environment/vibration and surface morphology of the thin films. © 2007 The Royal Swedish Academy of Sciences.