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| Format: | Preprint |
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2024
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| Online Access: | https://arxiv.org/abs/2408.09808 |
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| _version_ | 1866917883442888704 |
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| author | Yang, Jiyuan Liu, Shi |
| author_facet | Yang, Jiyuan Liu, Shi |
| contents | Many dipolar topological structures have been experimentally demonstrated in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices, such as flux-closure, vortice, and skyrmion. In this work, we employ deep potential molecular dynamics (MD) to investigate the dynamical response of the (PbTiO$_3$)$_{10}$/(SrTiO$_3$)$_{10}$ superlattice, supporting polar vortex arrays, to temperature and electric field at the atomic level. Our simulations reveal a unique phase transition sequence from ferroelectric-like to antiferroelectric-like to paraelectric in the in-plane direction as temperature increases. In the ferroelectric-like state, we observe field-driven reversible switching of in-plane polarization coupled with out-of-plane movements of vortex cores during MD simulations. In the antiferroelectric-like region, the polarization-electric field hysteresis loop exhibits a superparaelectric feature, showing nearly no loss. This behavior is attributed to a strong recovering force to form polar vortex arrays, dictated by the electrical and mechanical boundary conditions within the superlattice. The (PbTiO$_3$)$_{10}$/(SrTiO$_3$)$_{10}$ superlattice in the antiferroelectric-like state also demonstrates large in-plane susceptibility and tunability. The effect of Pb doping in the SrTiO$_3$ layer on the topological structural transition in the superlattice is investigated. The weakened depolarization field in the PbTiO$_3$ layers leads to new dipolar configurations, such as enlarged skyrmion bubble within $c$ domains in (PbTiO$_3$)$_{10}$/(Pb$_{0.4}$Sr$_{0.6}$TiO$_3$)$_{10}$, and we quantify their thermal and electrical responses through MD simulations. These quantitative atomistic insights will be useful for the controlled optimization of perovskite superlattices for various device applications. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2408_09808 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Topological phase transitions in perovskite superlattices driven by temperature, electric field, and doping Yang, Jiyuan Liu, Shi Materials Science Many dipolar topological structures have been experimentally demonstrated in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices, such as flux-closure, vortice, and skyrmion. In this work, we employ deep potential molecular dynamics (MD) to investigate the dynamical response of the (PbTiO$_3$)$_{10}$/(SrTiO$_3$)$_{10}$ superlattice, supporting polar vortex arrays, to temperature and electric field at the atomic level. Our simulations reveal a unique phase transition sequence from ferroelectric-like to antiferroelectric-like to paraelectric in the in-plane direction as temperature increases. In the ferroelectric-like state, we observe field-driven reversible switching of in-plane polarization coupled with out-of-plane movements of vortex cores during MD simulations. In the antiferroelectric-like region, the polarization-electric field hysteresis loop exhibits a superparaelectric feature, showing nearly no loss. This behavior is attributed to a strong recovering force to form polar vortex arrays, dictated by the electrical and mechanical boundary conditions within the superlattice. The (PbTiO$_3$)$_{10}$/(SrTiO$_3$)$_{10}$ superlattice in the antiferroelectric-like state also demonstrates large in-plane susceptibility and tunability. The effect of Pb doping in the SrTiO$_3$ layer on the topological structural transition in the superlattice is investigated. The weakened depolarization field in the PbTiO$_3$ layers leads to new dipolar configurations, such as enlarged skyrmion bubble within $c$ domains in (PbTiO$_3$)$_{10}$/(Pb$_{0.4}$Sr$_{0.6}$TiO$_3$)$_{10}$, and we quantify their thermal and electrical responses through MD simulations. These quantitative atomistic insights will be useful for the controlled optimization of perovskite superlattices for various device applications. |
| title | Topological phase transitions in perovskite superlattices driven by temperature, electric field, and doping |
| topic | Materials Science |
| url | https://arxiv.org/abs/2408.09808 |