Kink-pair mechanism and low temperature flow-stress behaviour of strontium titanate single crystals

Abstract

The mechanical behaviour of strontium titanate exhibits a remarkable behaviour at low temperature, in the so called regime A, where the flow stress experiences two different temperature dependences separated by a noticeably abrupt drop in between. The dislocation microstructure was investigated and, by making adequate use of the kink-pair model, we interpret this behaviour as a transition from the short- to the long-segment limit of kink-pair formation. The fit parameters are found to be physically sound.