Dislocations in plastically deformed SrTiO₃

Titanium enrichment and strontium depletion near edge dislocation in strontium titanate [001]/(110) low-angle tilt grain boundary

“…Dislocations in STO are believed to play a critical role in its mechanical deformation that exhibits unusual temperature dependence [11,12]. It has also been demonstrated that application of an electrical bias switches electrical conductivity along STO dislocations from a non-metallic to a metallic state [2].…”

Room-Temperature Plastic Deformation of Strontium Titanate Crystals Grown from Different Chemical Compositions

“…The mechanical properties of strontium titanate (SrTiO 3 ) crystals have received growing interest due to the fact that they can exhibit a large degree of plasticity even at low temperatures [3][4][5][6][7][8][9][10][11]. SrTiO 3 is an oxide with a cubic perovskite structure belonging to the Pm3m space group.…”

On low temperature glide of dissociated 〈1 1 0〉 dislocations in strontium titanate

“…Compared to previous work [19,20], the use of variable widths w 1 and w 2 implies potential changes in the total stacking fault area. The simultaneous nucleation of two kink-pairs is then associated with a variation of the elastic interaction energy composed of three terms, ΔE el = 2ΔE describes the variation in elastic energy between the partial lines (involving the interaction between segments K and K′, L and L′ in Figure 1(a)) and is given by Equation (8). …”

“…Brunner [7] subdivided regime A further into three regimes: A 1 (from 1050 K down to 225 K), A 2 (between 225 and 205 K) and A 3 (below 205 K). Transmission electron microscopy (TEM) observations of deformed SrTiO 3 single crystals have demonstrated that its microstructure was predominantly governed by 〈1 1 0〉{1 1 0} screw dislocations aligned with their Peierls potential minima along close packed directions in the perovskite structure [8,12] over the whole temperature range of regime A [7], thus discarding the hypothesis of a change of slip system to explain the non-monotonous mechanical behaviour. Both TEM at room temperature [9] and high-resolution transmission electron microscopy (HRTEM) below room temperature [11,12] of strained SrTiO 3 single crystals revealed that 〈1 1 0〉 screw dislocations are systematically dissociated by glide in {1 1 0} planes in the whole temperature range of regime A, impeding the hypothesis of a change in core structure of these dislocations.…”

“…stacking faults, dislocations) is of paramount importance. The mechanical behaviour of strontium titanate has turned out to be complex over a wide temperature range [5][6][7][8][9][10][11][12][13][14]. Despite its brittleness at high temperatures between 1050 and 1270 K [5,8], this oxide ceramic with a perovskite structure deforms in a ductile regime at temperatures below 1050 K, now commonly referred to as regime A [5][6][7][8]12].…”