The effect of annealing on the structure and dielectric properties of BaxSr1-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) have been measured. The films were grown by pulsed laser deposition on LaAlO3 (001) substrates. The films were single phase and (001) oriented with a lattice parameter larger than the bulk. The dielectric properties 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.