Investigation of the electrical properties of [111] oriented PbZrO3 thin films obtained by sol-gel process

Abstract

Lead zirconate-PbZrO3 (PZ) thin films were produced on Pt-(III)/Ti/SiO2/Si-(100) substrates by sol-gel spin coating using precursor solutions of various molarities and with various thicknesses. Increasing molarity and thickness led to further crystallization and grain growth in the films. Double polarization vs electric field hysteresis loops with square-like shapes were obtained due to fully [111] pseudo-cubic orientation. The maximum polarization of well-crystallized PZ films (200-400 nm) reaches 48 mu C/cm(2) under 400 kV/cm applied field, with switching fields between 270- 300 kV/cm in the forward direction and 150-180kV/cm in the reverse direction at room temperature. Increasing crystallinity of the films led to lower leakage current densities on the order of 10(-6) A/cm(2) or less. The room temperature dielectric constant of the PZ films was measured to be 240 with a Curie temperature of 240 degrees C. Temperature dependent P-E hysteresis measurements indicated a shift in the forward and reverse switching fields towards lower field levels as the temperature of measurement increased.