Functional Properties of Ferroic Domain Walls

近年来，铁性特别是多铁性材料由于其磁性、电性和弹性之间的潜在耦合性而受到了广泛的研究。畴壁（DWs）通常出现在这些材料中，本质上是二维纳米物体，通常具有与宿主材料不同的性质。历史上，DWs的性质被简单地忽略了，因为研究的重点是域本身的控制和行为。区域之间的边界被视为无关紧要的微小微观结构组成部分。直到最近才表明，DWs可能表现出与宿主材料不同的功能特性。它们可能是极性的，而宿主材料是不导电的，甚至在周围绝缘的情况下是超导的。发现的最重要的效应之一与增强的畴壁电子输运有关。金属性质、二维电子气体和自旋输运4已经被宣称，但到目前为止，在DWs中实现电子输运的深入表征方面还做得很少。该项目主要旨在了解铁畴壁的电子输运和传导机制，以及其他功能特性，如自旋或热输运。研究项目包括：确定最合适的宏观和纳米表征方法来确定DWs.II的目标功能特性。基于我们的新型低温矢量磁场和光辅助扫描探针显微镜开发表征方法。我们的具体目标是开发飞行时间和纳米霍尔实验来绘制载流子电荷密度，迁移率和扩散系数在畴壁。参考文献：1 S. Van Aert， S. Turner， R. Delville， D. Schryvers， G. Van Tendeloo， E. K. H. Salje, ad . Mater. 2012,24, 523。[2]张建军，等。自然科学进展。2009,8,229。3 A。Aird， M. C. Domeneghetti， F. Mazzi， V. Tazzoli， E. K. H. Salje， J. Phys。气孔导度。物质，1998,10,L569。4 j·h·李,国际泳联,x马蒂,d . Hesse黄懿慧Kim和m . Alexe先进材料26日,7078(2014)。

Ferroic and especially multiferroic materials have been intensively investigated in the last years for their exciting properties mostly given by the potential coupling between magnetic, electric and elastic properties. Domain walls (DWs) that usually occur in these materials are intrinsically two dimensional nano-objects which usually possess different properties than the host material. Historically, DWs properties were simply disregarded, as the research focused on the control and behaviour of the domains themselves. Boundaries between domains were dismissed as minor microstructural components of little significance. Only very recently has been shown that DWs might show functional properties different than the host material. They might be polar while the host material is not1, conductive2, or even superconductive when the surrounding is insulating.3One of the most important effects discovered was related to enhanced electronic transport at the domain walls. Metallic properties, 2D electron gas and spin transport 4 have been claimed, but so far little has been done to achieve an in-depth characterisation of the electronic transport at the DWs.The project seeks primarily to understand electronic transport and conduction mechanisms at the ferroic domain walls, as well as other functional properties such as spin or heat transport. The research program comprisesI. Identifying most appropriate both macroscopic and nanoscopic characterisation methods to determine the targeted functional properties of DWs.II. Developing characterisation methods based on our new low-temperature vector magnetic field and light assisted scanning probe microscope. We specifically aim to develop time-of-flight and nano-Hall experiments to map carrier charge density, mobility and diffusion coefficient at domain walls.References: 1 S. Van Aert, S. Turner, R. Delville, D. Schryvers, G. Van Tendeloo, E. K. H. Salje, Adv. Mater. 2012, 24, 523. 2 J. Seidel, et al., Nature Mater. 2009, 8, 229. 3 A. Aird, M. C. Domeneghetti, F. Mazzi, V. Tazzoli, E. K. H. Salje, J. Phys. Cond. Matter. 1998, 10, L569. 4 J. H. Lee, I. Fina, X. Marti, Y. H. Kim, D. Hesse, and M. Alexe, Advanced Materials 26, 7078 (2014).