Acevedo-Salas Ulises, Croes Boris, Zhang Yide, Cregut Olivier, Dorkenoo Kokou Dodzi, Kirbus Benjamin, Singh Ekta, Beccard Henrik, Rüsing Michael, Eng Lukas M, Hertel Riccardo, Eliseev Eugene A, Morozovska Anna N, Cherifi-Hertel Salia
Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 67034Strasbourg, France.
Institute of Applied Physics, Technische Universität Dresden, 01062Dresden, Germany.
Nano Lett. 2023 Feb 8;23(3):795-803. doi: 10.1021/acs.nanolett.2c03579. Epub 2023 Jan 20.
Ferroelectric domain boundaries are quasi-two-dimensional functional interfaces with high prospects for nanoelectronic applications. Despite their reduced dimensionality, they can exhibit complex non-Ising polarization configurations and unexpected physical properties. Here, the impact of the three-dimensional (3D) curvature on the polarization profile of nominally uncharged 180° domain walls in LiNbO is studied using second-harmonic generation microscopy and 3D polarimetry analysis. Correlations between the domain-wall curvature and the variation of its internal polarization unfold in the form of modulations of the Néel-like character, which we attribute to the flexoelectric effect. While the Néel-like character originates mainly from the tilting of the domain wall, the internal polarization adjusts its orientation due to the synergetic upshot of dipolar and monopolar bound charges and their variation with the 3D curvature. Our results show that curved interfaces in solid crystals may offer a rich playground for tailoring nanoscale polar states.
铁电畴界是具有纳米电子应用高前景的准二维功能界面。尽管它们的维度降低了，但仍可呈现复杂的非伊辛极化构型和意想不到的物理性质。在此，利用二次谐波产生显微镜和三维偏振分析研究了三维（3D）曲率对铌酸锂中名义上不带电的180°畴壁极化分布的影响。畴壁曲率与其内部极化变化之间的相关性以类奈尔特性调制的形式展现，我们将其归因于挠曲电效应。虽然类奈尔特性主要源于畴壁的倾斜，但内部极化由于偶极和单极束缚电荷的协同作用及其随三维曲率的变化而调整其取向。我们的结果表明，固体晶体中的弯曲界面可能为定制纳米级极化态提供一个丰富的平台。
