On low temperature glide of dissociated < 110 > dislocations in strontium titanate

An elastic interaction model is presented to quantify low temperature plasticity of SrTiO3 via glide of dissociated {110} screw dislocations. Because dislocations are dissociated, their glide, controlled by the kink-pair mechanism at T{110} glide mechanism, from simultaneous nucleation of two kink-pairs along both partials at low stress, towards nucleation of single kink-pairs on individual partials if resolved shear stress exceeds a critical value of 95MPa. High resolved shear stress allows thus for the activation of extra nucleation mechanisms on dissociated dislocations impossible to occur under the sole action of thermal activation. We suggest that stress condition in conjunction with core dissociation is key to the origin of non-monotonic plastic behaviour of SrTiO3 at low temperatures