THE EFFECT OF ANNEALING ON THE STRUCTURE AND DIELECTRIC-PROPERTIES OFBAXSR1-XTIO3 FERROELECTRIC THIN-FILMS

The effect of a postdeposition anneal on the structure and dielectric properties of epitaxial BaxSr1-xTiO3 (BST) thin films (x=0.35-0.65) ha ve been measured. The films were grown by pulsed laser deposition on L aAlO3 (001) substrates. The films were single phase and (001) oriented with a lattice parameter larger than the bulk. The dielectric propert ies of the x=0.35 film exhibited a broad temperature dependence and a peak at 168 K, which is 36 K below the peak observed in bulk BST (x=0. 35). Annealing films for 8 h in flowing oxygen at 900 degrees C caused the lattice parameter to decrease and dielectric properties to become more like the bulk. Annealing also resulted in an increased electric field dependent dielectric tuning without increased dielectric loss. ( C) 1996 American Institute of Physics.