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arXiv · 2502.02184

Dislocations and plasticity of KTaO$_3$ perovskite modeled with a new interatomic potential

Pierre Hirel·Franck Junior Kakdeu Yewou·Jiawen Zhang·Wenjun Lu·Xufei Fang·Philippe Carrez
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Abstract

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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Pierre Hirel, Franck Junior Kakdeu Yewou, Jiawen Zhang, Wenjun Lu, Xufei Fang, Philippe Carrez. 2025-02-04. Dislocations and plasticity of KTaO$_3$ perovskite modeled with a new interatomic potential. https://arxiv.org/abs/2502.02184

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