Preparation and tunability properties of Ba(ZrxTi1-x)O-3 thin films grown by a sol-gel process

Ba(ZrxTi1-x)O-3 (BZT) thin films were deposited via sol-gel process on LaNiO3, as buffer layer, and Pt-coated silicon substrates. The BZT films were perovskite phase and showed a (10 0) preferred orientation dependent upon zirconium content. The grain size decreased and the microstructure became dense with increasing zirconium content. The addition of Zr to the BaTiO3 lattice decreased the grain size of the crystallized films. The temperature dependent dielectric constant revealed that the thin films have relaxor behavior and diffuse phase transition characteristics that depend on the substitution of Zr for Ti in BaTiO3. The dependence of electrical properties on film thickness has been studied, with the emphasis placed on dielectric nonlinear characteristics. Ba(Zr0.35Ti65)O-3 thin films with weak temperature dependence of tunability in the temperature range from 0 to 130 degrees C could be attractive materials for situations in which precise control of temperature would be either impossible or too expensive. (c) 2005 Elsevier Ltd. All rights reserved.