Theoretical investigation of {110} generalized stacking faults and their relation to dislocation behavior in perovskite oxides

Hirel, Pierre; Márton, Pavel; Mrovec, Matous; Elsässer, Christian

doi:10.1016/j.actamat.2010.07.025

Cited by 41 publications

(49 citation statements)

References 43 publications

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“…The 〈1 1 0〉 dislocations dissociate into (collinear) partials following the Burgers vector reaction: 〈1 10 〉 → ½〈1 1 0〉 + ½〈1 1 0〉, partial dislocations being separated by an antiphase boundary (APB). The latter has been confirmed by theoretical calculations of the core structure of 〈1 1 0〉 dislocations in SrTiO 3 [13][14][15]. Deformed single crystal microstructure being predominantly composed of straight 〈1 1 0〉 screw dislocations, together with the general (albeit non-monotonic) increase in CRSS with decreasing temperature, are typical signs of lattice friction controlled plasticity in the low temperature regime A, characterised by stress-assisted thermally activated dislocation glide.…”

Section: Introductionsupporting

confidence: 55%

“…For a given applied stress, the metastable kink-pair configuration corresponds to a saddle point of the total energy variation (9) Figure 2. Peierls potential V p and Peierls force Σ of 〈1 1 0〉{1 1 0} screw dislocations based on previous atomistic simulations [13,14] and calculated in the framework of the Peierls-nabarro model. The Peierls stress τ p = 500 gPa is equal to the maximum of Σ.…”

Section: Resultsmentioning

confidence: 99%

“…To compute V p as shown in Figure 2, we use the γ-surface calculations of Hirel et al [13], and u m is derived from the dislocation core structure provided by Hirel et al [14]. It yields a Peierls stress τ p = 500 GPa.…”

Section: Modelling the Kink-pair Mechanismmentioning

confidence: 99%

“…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].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Ritterbex

Hirel

Carrez

2018

Philosophical Magazine

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An elastic interaction model is presented to quantify low temperature plasticity of SrTiO 3 via glide of dissociated 〈1 1 0〉{1 1 0} screw dislocations. Because 〈1 1 0〉 dislocations are dissociated, their glide, controlled by the kink-pair mechanism at T < 1050 K, involves the formation of kink-pairs on partial dislocations, either simultaneously or sequentially. Our model yields results in good quantitative agreement with the observed non-monotonic mechanical behaviour of SrTiO 3 . This agreement allows to explain the experimental results in terms of a (progressive) change in 〈1 1 0〉{1 1 0} glide mechanism, from simultaneous nucleation of two kinkpairs along both partials at low stress, towards nucleation of single kink-pairs on individual partials if resolved shear stress exceeds a critical value of 95 MPa. 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 SrTiO 3 at low temperatures.

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Section: Introductionsupporting

confidence: 55%

Section: Resultsmentioning

confidence: 99%

Section: Modelling the Kink-pair Mechanismmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Ritterbex

Hirel

Carrez

2018

Philosophical Magazine

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“…According to the studies by Thomas et al [34], Benedeck et al [35] and Hirel et al [36], the rigid-ion potential developed by Thomas et al [37] for STO behaves even better in comparing with experimental and ab initio data of elastic constants, lattice parameter, formation energy of defects and stacking faults energy than some shell-model potentials. Hirel et al [38] successfully used this potential in an atomistic simulation to study the mechanical behaviour of edge and screw dislocations in STO.…”

Section: Computational Models and Simulation Results (A) Interatomic mentioning

confidence: 99%

Concurrent atomistic and continuum simulation of bi-crystal strontium titanate with tilt grain boundary

Yang

Chen

2015

Proc. R. Soc. A.

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In this paper, we present the development of a concurrent atomistic-continuum (CAC) methodology for simulation of the grain boundary (GB) structures and their interaction with other defects in ionic materials. Simulation results show that the CAC simulation allows a smooth passage of cracks through the atomistic-continuum interface without the need for additional constitutive rules or special numerical treatment; both the atomic-scale structures and the energies of the four different [001] tilt GBs in bicrystal strontium titanate obtained by CAC compare well with those obtained by existing experiments and density function theory calculations. Although 98.4% of the degrees of freedom of the simulated atomistic system have been eliminated in a coarsely meshed finite-element region, the CAC results, including the stress-strain responses, the GB-crack interaction mechanisms and the effect of the interaction on the fracture strength, are comparable with that of all-atom molecular dynamics simulation results. In addition, CAC simulation results show that the GBcrack interaction has a significant effect on the fracture behaviour of bi-crystal strontium titanate; not only the misorientation angle but also the atomic-level details of the GB structure influence the effect of the GB on impeding crack propagation.

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Antisite Defects Stabilized by Antiphase Boundaries in YFeO₃ Thin Films

Kumar

Klyukin

Ning

et al. 2021

Adv Funct Materials

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YFeO3 thin films are a recent addition to the family of multiferroic orthoferrites where YFe antisite defects and strain have been shown to introduce polar displacements while retaining magnetic properties. Complete control of the multiferroic properties, however, necessitates knowledge of the defects present and their potential role in modifying behavior. Here, the structure and chemistry of antiphase boundaries in Y‐rich multiferroic YFeO3 thin films are reported using aberration corrected scanning transmission electron microscopy combined with atomic resolution energy dispersive X‐ray spectroscopy. It is found that FeY antisites, which are not stable in the Y‐rich film bulk, periodically arrange along antiphase boundaries due to changes in the local structural environment. Using density functional theory, it is shown that the antiphase boundaries are polar and bi‐stable, where the presence of FeY antisites significantly decreases the switching barrier. These results highlight how planar defects, such as antiphase boundaries, can stabilize point defects that would otherwise not be expected to form within the structure.

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Theoretical investigation of {110} generalized stacking faults and their relation to dislocation behavior in perovskite oxides

Cited by 41 publications

References 43 publications

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

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

Concurrent atomistic and continuum simulation of bi-crystal strontium titanate with tilt grain boundary

Antisite Defects Stabilized by Antiphase Boundaries in YFeO₃ Thin Films

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Theoretical investigation of {110} generalized stacking faults and their relation to dislocation behavior in perovskite oxides

Cited by 41 publications

References 43 publications

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

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

Concurrent atomistic and continuum simulation of bi-crystal strontium titanate with tilt grain boundary

Antisite Defects Stabilized by Antiphase Boundaries in YFeO3 Thin Films

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Antisite Defects Stabilized by Antiphase Boundaries in YFeO₃ Thin Films