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arXiv · 2609.07219

Atomistic origin and strain control of the finite-temperature dielectric response in BaTiO3

Ryotaro Sahashi·Po-Yen Chen·Teruyasu Mizoguchi
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Abstract

The dielectric response of BaTiO3 (BTO) varies strongly with temperature, yet its local atomic origin remains unclear. Using electric-field-coupled molecular dynamics with a machine-learning force field, we show that the permittivity tracks the field-induced angular redistribution of local Ti-O off-centering rather than its magnitude or mean polar angle. Temperature and biaxial strain modify the local structure differently, but both responses follow a common relation with the same orientational descriptor, providing a real-space counterpart to soft-mode behavior.

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Ryotaro Sahashi, Po-Yen Chen, Teruyasu Mizoguchi. 2026-09-07. Atomistic origin and strain control of the finite-temperature dielectric response in BaTiO3. https://arxiv.org/abs/2609.07219

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