Eremenko Maksim, Krayzman Victor, Gorfman Semen, Bosak Alexei, Playford Helen Y, Chater Philip A, Ravel Bruce, Laws William J, Ye Feng, Minelli Arianna, Wang Bi-Xia, Ye Zuo-Guang, Tucker Matthew G, Levin Igor
Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
Nat Commun. 2025 Aug 13;16(1):7531. doi: 10.1038/s41467-025-62658-1.
Relaxor ferroelectrics underpin high-performance actuators and sensors, yet the nature of polar heterogeneities driving their broadband dielectric response remains debated. Using a unified, multimodal structural refinement framework- simultaneously fitting complementary X-ray and neutron total scattering, X-ray absorption spectra, and diffuse scattering-we reconstruct 3D mesoscale polarization maps in the classic relaxor system PbMgNbO-PbTiO. We uncover self-organized swirling polarization textures with half-skyrmion (meron) vortices, challenging models of independent polar nanoregions. These textures, characterized by smooth changes in the polarization direction, originate from overlapping volumes in which the projections of locally correlated polarization vectors onto each volume's long axis share the same sign. Vortex cores correlate strongly with local charge and strain gradients imposed by compositional heterogeneities. In this work, our results suggest that chemical disorder, acting via depolarizing and strain fields, stabilizes topological vortex textures of the polarization field, offering a route for engineering new dielectric and ferroelectric functionalities.
弛豫铁电体是高性能致动器和传感器的基础,然而驱动其宽带介电响应的极性不均匀性的本质仍存在争议。我们使用一个统一的多模态结构精修框架——同时拟合互补的X射线和中子全散射、X射线吸收光谱以及漫散射——在经典弛豫体系PbMgNbO-PbTiO中重建了三维中尺度极化图。我们发现了具有半斯格明子(默子)涡旋的自组织涡旋极化纹理,这对独立极性纳米区域模型提出了挑战。这些纹理的特征是极化方向的平滑变化,源自重叠体积,其中局部相关极化矢量在每个体积长轴上的投影具有相同的符号。涡旋核心与由成分不均匀性引起的局部电荷和应变梯度密切相关。在这项工作中,我们的结果表明,通过去极化场和应变场起作用的化学无序稳定了极化场中的拓扑涡旋纹理,为设计新的介电和铁电功能提供了一条途径。