Dislocations and plasticity of KTaO3 perovskite modeled with an interatomic potential

P Hirel and FJK Yewou and JW Zhang and WJ Lu and XF Fang and P Carrez, PHYSICAL REVIEW MATERIALS, 9, 053605 (2025).

DOI: 10.1103/PhysRevMaterials.9.053605

Potassium tantalate KTaO3 is a cubic, paraelectric perovskite ceramic that exhibits surprising ductility at room temperature as most recently reported. Much like strontium titanate (SrTiO3), plastic deformation is accommodated by dislocations gliding in 110 planes. In this work, we propose a new interatomic potential for KTaO3, and apply it to model dislocations with (110) Burgers vector. We demonstrate that dislocations dissociate, and finely characterize their core structure and Peierls potential. Dislocations of edge character can carry a positive or negative electric charge, but we show that charge-neutral configurations are energetically more favorable. We also perform high-resolution electron microscopy to validate our simulation methodology. Comparing our results with other ductile perovskites, we confirm KTaO3 to be ductile, but stiffer than SrTiO3.

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