SrBi2Ta2O9-based electroceramics and thin films

Abstract

<P>ABSTRACT</P><P>IN THIS PROJECT, BISMUTH-LAYERED PEROVSKITE SRBI2TA2O9 (SBT) AND W-DOPED SBT [SRBI2(TA1-XWX)2O9] WERE SUCCESSFULLY SYNTHESIZED VIA A MECHANICAL ACTIVATION PROCESSING ROUTE. STUDIES WERE CARRIED OUT TO UNDERSTAND THE MECHANISMS INVOLVED IN THE PHASE FORMATION, AND FERROELECTRIC AND DIELECTRIC PROPERTIES OF THUS DERIVED ELECTROCERAMIC MATERIALS. THE IMPROVED SINTERABILITY IS DUE TO THE NANOCRYSTALLINITY DERIVED FROM MECHANICAL ACTIVATION. THE RESULTING ENHANCEMENT IN THE DIELECTRIC PROPERTIES OF THE W-DOPED SBT WERE FOUND TO RESULT FROM THE EFFECTIVE SUPPRESSION OF OXYGEN VACANCIES, BROUGHT ABOUT BY SUBSTITUTION OF TA5+ BY W6+, AND THE DISTORTION OF THE SBT LATTICE. ON THE BASIS OF THE STUDIES MADE WITH THE BULK ELECTROCERAMICS, THIN FILMS OF LAYERED PEROVSKITE SBTW WERE SYNTHESIZED BY OFF-AXIS RADIO FREQUENCY SPUTTERING, IN ORDER TO EXAMINE THE FERROELECTRIC AND ELECTRICAL PROPERTIES OF THESE MATERIALS IN THIN FILM FORMS.</P>