  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.
