Influence of texturizing and crystalline deffects on the ferroelectric properties of thin films and ceramics

Abstract

This proposal is a continuation of the multidisciplinary research in ferroelectric thin films and ceramics being developed in the thematic project FAPESP 00/01991-0, by researchers of the Interdisciplinary Research on Ceramics Laboratory (LIEC). The main objective is to promote a quality substantial improvement on the understanding of these films and ceramics, when compared with previous research developed by the group. In this project, the main goal is to understand how the distribution and orientation of ferroelectric domains as well as the texturization affects the electrical properties of films and ceramics. Ferroelectric, dielectric, piezoelectric, relaxor and electrostictive properties will be evaluated and related to the crystalographical, microstructural and chemical composition of materials aiming to establish the influence in fadigue, retention and imprint characteristics of the systems. For that, films and ceramics will be processed, in amorphous or crystalline form, by using chemical process (polymeric precursor method) and physical ("RF-Magnetron sputtering") aiming to obtain equal or superior properties to that obtained by other methods reported in the literature. The properties of the ferroelectric ceramics will be optimized through the processing control to obtain microstructure and chemical homogeneity in the ceramics. Anysotropic crystals as templates will also be used aiming to improve the films and ceramics properties. Ferroelectric thin films will be processed in adequate substrates controlling the chemical homogeneity, the microstructure and the interaction with the electrode, aiming to obtain superior ferroelectric properties. The thermal treatment, important in the processing of films and ceramics, will be carefully optimized by using alternative routes as the microwave furnace which avoids interfacial reactions allowing better densification with reduced time, resulting in efficiency and economy. Therefore, by controlling the synthesis process, crystallization and sintering is possible to obtain films and ceramics with ferroelectric, dielectric and piezoelectric properties required to the following applications: capacitors, actuators, FeRAMs and DRAM memories, "displays", modulators and sensors. (AU)