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arXiv · 1911.02634

Twin Boundary Mediated Flexoelectricity in LaAlO$_3$

Christopher A. Mizzi·Binghao Guo·Laurence D. Marks
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Abstract

Flexoelectricity has garnered much attention owing to its ability to bring electromechanical functionality to non-piezoelectric materials and its nanoscale significance. In order to move towards a more complete understanding of this phenomenon and improve the efficacy of flexoelectric-based devices, it is necessary to quantify microstructural contributions to flexoelectricity. Here we characterize the flexoelectric response of bulk centrosymmetric LaAlO$_3$ crystals with different twin boundary microstructures. We show that twin boundary flexoelectric contributions are comparable to intrinsic contributions at room temperature and enhance the flexoelectric response by ~4x at elevated temperatures. Additionally, we observe time-dependent and non-linear flexoelectric responses associated with strain-gradient-induced twin boundary polarization. These results are explained by considering the interplay between twin boundary orientation, beam-bending strain fields, and pinning site interactions.

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Christopher A. Mizzi, Binghao Guo, Laurence D. Marks. 2019-11-06. Twin Boundary Mediated Flexoelectricity in LaAlO$_3$. https://doi.org/10.1103/physrevmaterials.5.064406

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