Preferential orientation of modified SrBi2Nb2O9 ferroelectric thin films prepared by pulsed laser deposition

We report on the deposition of SrBi2Nb2O9 and Sr1-xNaxBi2-xTexNb2O9 ferroel ectric thin films on Pt/TiO2/SiO2/(100) Si substrates using the pulsed lase r deposition technique. Deposition on substrates heated to 600-700 degrees C produces {11l} film texture and dense films with grain sizes up to about 500 nm. The recrystallization at 700 degrees C of amorphous films deposited at lower temperatures enhances the contribution of the {100} and {010} ori entations. These films show smaller grain size, namely 50-100 nm. {11l}-ori ented Sr1-xNaxBi2-xTexNb2O9 films have remnant polarization P-r similar or equal to 14 mu C/cm(2), a coercive field E-c similar or equal to 60 kV/cm a nd dielectric constant, epsilon similar or equal to 300. The low value of P -r is probably related to the low fraction of grains with the ferroelectric axis in the direction of the applied field, E. The recrystallized films ha ve more grains with the ferroelectric axis parallel to E; however, they hav e a low resistivity which so far has prevented electrical characterization.