Ferroelectric thin films of bismuth strontium tantalate prepared by alkoxide route

Study of the interactions in Bi(OR)(3)-Ta(OR)(5)-ROH (R = Me, Et, Pr-i) at 20 degrees C show that metal ethoxides are the best of the investigated pre cursors for the production of bismuth tantalates via alkoxides. Polycrystal line SrBi2Ta2O9 (SBTO) and BiTaO4 films on Si-SiO2-Ti-Pt substrates with th icknesses of 0.4-0.5 mu m and 0.4 mu m, respectively, have been formed by s ol-gel processing. The most stable solutions for film application were obta ined by using mixed-metal Bi-Ta ethoxides and solutions of Sr carboxylate ( 2-ethylhexanoic acid derivative) in 2-ethylhexanoic acid. Films annealed at 700-750 degrees C for 30 min were single-phased. SBTO films demonstrated g ood ferroelectric properties: remanent polarization ranged from 3.5 to 4.0 mu C/cm(2) and coercive voltage 1.5-2.0 V, whereas BiTaO4 films showed diel ectric behavior.