PREPARATION OF FERROELECTRIC THIN-FILMS FROM WATER-SOLUBLE TITANATE-BASED GELS

A description is made of a wet chemical method for obtaining ferroelec tric thin films. The processing is based on a twofold synthetic scheme : the synthesis of a titanate gel from a sol-gel process and the rehyd ration of this gel during the incorporation into the system of other i ons as water-soluble salts. The versatility of this route has made pos sible preparation of modified lead titanate precursor solutions. Alkal ine earth ions or lanthanides such as Ca2+ or Sm3+, have been used as modifier elements. Physico-chemical properties of the solutions are st udied as well as the reaction mechanisms that make possible the rehydr ation of the titanate gel. The solutions obtained are used for the dep osition and crystallization of titanate based thin films. Crystallinit y, microstructure and polarization-electrid field characteristics of t he films are shown.