The defect structure of a 350nm-thick epitaxial Ba0.3Sr0.7TiO3 film, grown onto (001)LaAlO3, was investigated by using conventional and high-resolution transmission electron microscopy. The predominant defects in the film were edge-type threading dislocations with Burgers vectors of b = <100> or <110>. Pure-screw threading dislocations, and partial threading dislocations of mixed character, were also observed. A rapid reduction in defect density occurred after growth of the first 100nm of (Sr,Ba)TiO3 adjacent to the interface. In the upper layer of the film, all of the threading dislocations with b = <100> were perfect, while those with b = <110> were usually dissociated into 2

partials with a separation of a few nm. In the near-interface layer of the film, many threading dislocations with b = <100> were split into 2 or 3 partials. A high density of extended stacking faults with displacement vectors of ½<110>-type was observed. The stacking faults were associated with dissociated dislocations and partial half-loops.

Dissociation and Evolution of Threading Dislocations in Epitaxial Ba0.3Sr0.7TiO3 Thin Films Grown on (001) LaAlO3. C.J.Lu, L.A.Bendersky, K.Chang, I.Takeuchi: Journal of Applied Physics, 2003, 93[1], 512-21