Abstract
The systematic investigation on the piezoelectric properties of lanthanum-substituted lead zirconate titanate (PLZT) films was carried out. Polycrystalline PLZT films with La-contents of 0, 3, 6, 9 and 12 mol% were formed on Pt/Ti/SiO2/Si substrates at 700 oC by chemical solution deposition (CSD). 111 preferred oriented PLZT films were directly grown on the substrates, and PZT seeding layers were introduced onto substrates for randomly oriented PLZT films. The longitudinal displacement curves were measured with D-E hysteresis loops simultaneously at ±300 kV/cm by AFM probing system. The maximum longitudinal displacements were attained at La content of 6 mol% in both orientations. The change in optical length induced by the longitudinal displacement was estimated to be from 0.2 to 0.4%. On the other hand, the shift in resonant wavelength induced by applying DC bias voltage is typically to be 0.5 to 1.0% in PLZT films. Therefore, we concluded that the influence of piezoelectric displacements on electrooptic effect is not small.
