HRTEM Study on the Extended Defect Structure of Epitaxial Ba0.3Sr0.7Ti03 thin films Grown on (001) LaAl03
C J. Lu, Leonid A. Bendersky, K S. Chang, Ichiro Takeuchi
The defect structure of a 350-nm-thick epitaxial Ba0.3Sr0.7Ti03 thin film grown on (001) LaAl03 has been investigated by means of conventional and high-resolution transmission electron microscopy. The predominant defects in the film are a high density of threading dislocations with Burgers vectors b = and . A high density of extended stacking faults with displacement vectors R = (1/2) were also observed in the near-interface region of the film. The faults are associated with dissociated dislocations and partial halfloops. Some findings about dislocation dissociation and the atomic structure of the (1/2) faults are observed for the first time in perovskites. The mechanisms for the generation, dissociation and evolution of the TDs as well as for the formation mechanism of the SFs are discussed.