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arXiv · 1001.2271

Effect of strain and oxygen vacancies on the structure of 180^o ferroelectric domain walls in PbTiO_3

Arzhang Angoshtari·Arash Yavari
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Abstract

In this paper we study the effect of normal and shear strains and oxygen vacancies on the structure of 180^o ferroelectric domain walls in PbTiO_3. It is known that oxygen vacancies move to the domain walls and pin them. Hence, we assume a periodic arrangement of oxygen vacancies on both Pb-centered and Ti-centered domain walls in PbTiO_3. We use a semi-analytic anharmonic lattice statics method for obtaining the relaxed configurations using a shell potential. In agreement with recent ab initio calculations, we observe that a Pb-centered domain wall with oxygen vacancies is not stable even under strain. Our semi-analytic calculations for PbTiO_3 show that oxygen vacancies affect the structure of 180^o domain walls significantly but do not have a considerable effect on the thickness of domain walls; they broaden the domain walls by about fifty percent. We also study the effect of normal and shear strains on both perfect and defective 180^o domain walls. We observe that normal and shear strains affect the structure but do not change the domain wall thickness.

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Arzhang Angoshtari, Arash Yavari. 2010-01-13. Effect of strain and oxygen vacancies on the structure of 180^o ferroelectric domain walls in PbTiO_3. https://arxiv.org/abs/1001.2271

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