Perovskite barium strontium titanate Ba0.5Sr0.5TiO3(BST) thin films were gr
own on (001) LaAlO3 (LAO) using pulsed-laser ablation. The microstructures
of the as-grown BST films were studied with selected electron diffraction,
transmission electron microscopy, and scanning transmission electron micros
copy. The BST thin films are oriented with their [001] directions parallel
to the < 102 > directions of the LAO. Both cross-sectional and plan-view st
udies show the BST films to be single crystals with smooth surfaces. The in
terfaces were seen to be atomically sharp by cross-sectional, high-resoluti
on electron microscopy. The density of misfit dislocations was consistent w
ith the 4.3% lattice mismatch, and they were found to be dissociated into p
artials. (C) 1999 American Institute of Physics. [S0003-6951(99)00443-X].