Schultheiß Jan, Xue Fei, Roede Erik, Ånes Håkon W, Danmo Frida H, Selbach Sverre M, Chen Long-Qing, Meier Dennis
Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway.
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Adv Mater. 2022 Nov;34(45):e2203449. doi: 10.1002/adma.202203449. Epub 2022 Oct 13.
The research on topological phenomena in ferroelectric materials has revolutionized the way people understand polar order. Intriguing examples are polar skyrmions, vortex/anti-vortex structures, and ferroelectric incommensurabilties, which promote emergent physical properties ranging from electric-field-controllable chirality to negative capacitance effects. Here, the impact of topologically protected vortices on the domain formation in improper ferroelectric ErMnO polycrystals is studied, demonstrating inverted domain scaling behavior compared to classical ferroelectrics. It is observed that as the grain size increases, smaller domains are formed. Phase field simulations reveal that elastic strain fields drive the annihilation of vortex/anti-vortex pairs within the grains and individual vortices at the grain boundaries. The inversion of the domain scaling behavior has far-reaching implications, providing fundamentally new opportunities for topology-based domain engineering and the tuning of the electromechanical and dielectric performance of ferroelectrics in general.
铁电材料中拓扑现象的研究彻底改变了人们理解极性有序的方式。引人注目的例子包括极性斯格明子、涡旋/反涡旋结构以及铁电失配，这些现象促进了从电场可控手性到负电容效应等新兴物理特性的出现。在此，研究了拓扑保护涡旋对非本征铁电体ErMnO多晶体中畴形成的影响，结果表明与经典铁电体相比，其畴缩放行为发生了反转。观察到随着晶粒尺寸的增加，形成的畴更小。相场模拟表明，弹性应变场驱动晶粒内涡旋/反涡旋对以及晶界处单个涡旋的湮灭。畴缩放行为的反转具有深远意义，从根本上为基于拓扑的畴工程以及一般铁电体机电和介电性能的调谐提供了新的机会。
