LEAD-OXIDE COATINGS ON SOL GEL-DERIVED LEAD LANTHANUM ZIRCONIUM TITANATE THIN-LAYERS FOR ENHANCED CRYSTALLIZATION INTO THE PEROVSKITE STRUCTURE

An improved method is described for the sol-gel preparation of PLZT thin layers in the perovskite structure. The method uses a PbO cover coat. Details are reported for the sol-gel processing route and heat-treatment conditions. Through use of this method it is possible to prepare single-phase perovskite material with improved properties. The deleterious effect of additional phases-which are not present when a PbO cover coat is used-is attributed to Pb loss from the surface during thermal processing. Examples are given for PLZT thin layers integrated on Si with and without a PbO cover coat. The dielectric and ferroelectric properties were always found to be superior for coated structures.