SOL-GEL DERIVED SRBI2TA2O9 THIN-FILMS AND ELECTRICAL-PROPERTIES

Ferroelectric SrBi2Ta2O9 thin films were prepared from Sr metals, Ta-e thoxide and Bi, 2-ethylhexanoate. The films were prepared from both st oichiometric and 10 mol% Bi rich solutions. The stoichiometric film cr ystallized at 800 degrees C had a spontaneous polarization value of 5 mu C/cm(2). The Bi rich film had lower crystallinity, finer grains and a smaller polarization. It was found to be necessary to anneal the fi lms at high temperatures or for long time to achieve ferroelectricity. The non-crystalline states of sol-gel derived films differ from that observed in films deposited by physical vapor deposition. Crack free f ilms were produced with the film thicknesses of 0.4 mu m.