From glissile to sessile: Effect of temperature on < 110 > dislocations in perovskite materials
P Hirel and P Carrez and P Cordier, SCRIPTA MATERIALIA, 120, 67-70 (2016).
In perovsldte-type strontium titanate (SrTiO3) < 110 > dislocations, which are the main carriers of plastic flow at low temperature, lose their mobility as temperature increases, leading to brittle failure above 1050 K. We present theoretical evidence for a change in their core structure into a sessile, climb-dissociated configuration at high temperature. This mechanism is shown to operate in both SrTiO3 and MgSiO3, indicating that it may be a general feature of perovskite-type materials. It follows that the activity of the < 110 > slip system depends critically on the strain rate-temperature couple, ((epsilon) over dot, T). (C) 2016 Elsevier Ltd.
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