Lower temperature crystallization and ordering in sol-gel derived Pb(Sc/sub 0.5/Ta/sub 0.5/)O/sub 3/ powders and thin layers

Lead scandium tantalate (PST) was prepared by sol-gel processing, and the crystallization into the perovskite phase was determined at reduced temperatures (600-700/spl deg/C). The extent of B-site cation ordering was also determined as a function of cooling conditions. Results are reported for the integration of capacitors on silicon with a capacitance density greater than 200 fF//spl mu/m/sup 2/. A preferred (111) orientation was obtained, with ( 1/2 1/2 1/2 ) B-site cation partial ordering. No evidence was obtained for A-site Pb vacancy ordering. Results are reported for X-ray diffraction and selected-area electron diffraction investigations.