Properties Variation with Composition of Single-Crystal Pb(ZrxTi1−x,)O3 Thin Films Prepared by MOCVD

Abstract

AbstractSingle-crystal thin films covering the full compositional range of Pb(ZrxTi1−x)O3(PZT) 0≤x≤1 have been deposited by metal-organic chemical vapor deposition (MOCVD). The films were grown on epitaxial, RF-sputter-deposited SrRuO3 thin film electrodes on (001) SrTiO3 substrates. X-ray diffraction (XRD), energy-dispersive electron spectroscopy (EDS) and optical waveguiding were used to characterize the crystalline structure, composition, refractive index, and film thickness of the deposited films. We found that the PZT films were single-crystalline for all compositions exhibiting cube-on-cube epitaxy with the substrate with very high degrees of crystallinity and orientation. We report the systematic variations in the optical, dielectric, polarization, and transport properties as a function of composition and the epitaxy-induced modifications in the solid-solution phase diagram of this system. These films exhibited electronic properties which showed clear systematic variations with composition. High values of remnant polarization (30–55 μC/cm2) were observed at all ferroelectric compositions. Unlike previous studies, the dielectric constant exhibited a clear dependence on composition with values ranging from 225–650. The coercive fields decreased with increasing Zr concentration to a minimum of 20 kV/cm at the (70/30) composition. In addition, these films exhibited both high resistivity and dielectric-breakdown strength (˜1013 Ω-cm at 100 kV/cm and >300 kV/cm, respectively) without any compensative doping.