MEASUREMENT OF PIEZOELECTRIC COEFFICIENTS OF FERROELECTRIC THIN-FILMS

This article presents measurements of piezoelectric coefficients of le ad zirconate titanate (PZT) thin films. The normal load method is used to measure the coefficients for PZT films with various compositions p repared by the sol-gel technique or by organometallic chemical vapor d eposition (OMCVD). The as-deposited OMCVD films have a piezoelectric c oefficient of 20-40 X 10(-12) m/V whereas the unpoled sol-gel films ar e not piezoelectric. After poling the thin films having a composition near the morphotropic phase boundary; these values increase to 200 X 1 0(-12) m/V for OMCVD films and 400 x 10(-12) m/V for sol-gel films. Th e difference may arise from an incomplete poling of the OMCVD films.