MICROSTRUCTURAL DEVELOPMENT IN SOL-GEL DERIVED LEAD-ZIRCONATE-TITANATE THIN-FILMS - THE ROLE OF PRECURSOR STOICHIOMETRY AND PROCESSING ENVIRONMENT

The role of precursor stoichiometry and local firing environment on th e microstructural development of sol-gel derived lead zirconate titana te (PZT) thin films was investigated. Typically, excess Pb is added to films to compensate for PbO volatilization during heat treatment. Her e, it is shown that the use of stoichiometric precursors with either a PbO atmosphere powder or a PbO overcoat during the crystallization he at treatment is an attractive and viable alternative method for contro l of film stoichiometry. Using these approaches, we have fabricated si ngle phase perovskite thin films with microstructures and electrical p roperties (P-r similar to 36 mu C/cm(2) and E(c) similar to 45 kV/cm) comparable to those of films using optimized solution chemistries and excess Pb additions. The potential advantage of increasing PbO partial pressure, or activity, during firing versus excess Pb additions is di scussed from the standpoint of a proposed crystallization scenario bas ed on the kinetic competition between Pb loss and the nucleation and g rowth rates of the perovskite phase.