Dynamic Conductivity of Ferroelectric Domain Walls in BiFeO3
Dynamic Conductivity of Ferroelectric Domain Walls in BiFeO3
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DOI：
10.1021/nl104363x
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发表时间：
2011-05-01
期刊：
影响因子：
10.8
通讯作者：
Ramesh, Ramamoorthy
中科院分区：
文献类型：
--
作者：
Maksymovych, Peter;Seidel, Jan;Ramesh, Ramamoorthy
铁性材料中分离连续极化、磁化和应变域的拓扑壁有望获得新的电子特性，这些特性本质上局限于纳米级，并且可以根据需要进行图案化而不改变材料体积或元素组成。我们已经发现，铁电畴壁在多铁性BiFeO3是固有的动态电子导体，密切模仿忆阻行为和刚性导电性的通常假设相反。外加电场可以引起绝缘畴壁和导电畴壁之间的局部转变，将畴壁电导调谐超过一个数量级，并产生亚稳电导态的准连续谱。我们的测量结果表明，微妙的和微观可逆的扭曲的极化结构在畴壁是在起源的动态电导率。因此，后者可能是铁电半导体中拓扑缺陷的普遍性质。
Topological walls separating domains of continuous polarization, magnetization, and strain in ferroic materials hold promise of novel electronic properties, that are intrinsically localized on the nanoscale and that can be patterned on demand without change of material volume or elemental composition. We have revealed that ferroelectric domain walls in multiferroic BiFeO3 are inherently dynamic electronic conductors, closely mimicking memristive behavior and contrary to the usual assumption of rigid conductivity. Applied electric field can cause a localized transition between insulating and conducting domain walls, tune domain wall conductance by over an order of magnitude, and create a quasicontinuous spectrum of metastable conductance states. Our measurements identified that subtle and microscopically reversible distortion of the polarization structure at the domain wall is at the origin of the dynamic conductivity. The latter is therefore likely to be a universal property of topological defects in ferroelectric semiconductors.