Holtz Megan E, Padgett Elliot S, Steinhardt Rachel, Brooks Charles M, Meier Dennis, Schlom Darrell G, Muller David A, Mundy Julia A
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2021 Apr 16;126(15):157601. doi: 10.1103/PhysRevLett.126.157601.
We construct ferroelectric (LuFeO_{3}){m}/(LuFe{2}O_{4}) superlattices with varying index m to study the effect of confinement on topological defects. We observe a thickness-dependent transition from neutral to charged domain walls and the emergence of fractional vortices. In thin LuFeO_{3} layers, the volume fraction of domain walls grows, lowering the symmetry from P6_{3}cm to P3c1 before reaching the nonpolar P6_{3}/mmc state, analogous to the group-subgroup sequence observed at the high-temperature ferroelectric to paraelectric transition. Our study shows how dimensional confinement stabilizes textures beyond those in bulk ferroelectric systems.
我们构建了具有不同指数m的铁电（LuFeO₃）ₘ/（LuFe₂O₄）超晶格，以研究限域对拓扑缺陷的影响。我们观察到从中性到带电畴壁的厚度依赖性转变以及分数涡旋的出现。在薄的LuFeO₃层中，畴壁的体积分数增加，在达到非极性P6₃/mmc状态之前，对称性从P6₃cm降低到P3c1，这类似于在高温铁电到顺电转变时观察到的群-子群序列。我们的研究表明了尺寸限域如何稳定超出体铁电系统中的织构。
