Dislocations in plastically deformed SrTiO₃

Abstract

Bright-field and weak-beam TEM investigations were performed on plastically deformed SrTiO₃. A gradual change from a⟨110⟩ edge-type to screw-type dislocations is found with decreasing temperature. It was found that edge dislocations undergo climb at high temperatures. In order to explain this plastic behaviour, a model is presented which is based on the temperature dependence of the dislocation core structures. At elevated temperatures edge dislocations dissociate by climb. This is impeded at low temperatures because of the lack of thermal activation. At low temperatures screw dislocations are assumed to become sessile, probably due to a non-planar dissociation of the dislocation core.

Acknowledgements

We are indebted to U. Salzberger and M. Sycha for the excellent TEM specimen preparation. Discussions with Prof. V. Vitek and Prof. A. H. Heuer are gratefully acknowledged. We thank the German Science Foundation for financial support of C.S. in the framework of the “Graduiertenkolleg”, GRK 285. We thank the referees for very helpful comments which allowed us to improve the paper.

Notes

†on leave from: National Institute for Materials Physics, Magurele-Bucharest, Romania.

Additional information

Notes on contributors

C. Sarbu†

†on leave from: National Institute for Materials Physics, Magurele-Bucharest, Romania.