It is now well‐established that ferroelectric domain walls, at which there are discontinuities in polarization, are usually electrically conducting. Yet, there is a dearth of rather basic information on the physics underpinning conductivity. Here, Kelvin Probe Force Microscopy (KPFM)‐based experiments are reported, which allow significant new insights regarding charge transport at domain walls in ErMnO3. In one set of experiments, KPFM is used to spatially map the Hall potential, developed at the surface of polished single crystals. These maps provide direct experimental evidence that n‐type head‐to‐head domain walls arise in otherwise p‐type material. In another set of experiments, the geometry for current flow is restricted, by cutting sub‐micron thick lamellar slices of ErMnO3 (using a Focused Ion Beam microscope). Separate contacts are made to n and p‐type walls and the potential profiles, when driving source‐drain currents, are measured (again using KPFM). Current‐electric field functions showed Ohmic behaviour for p‐type walls, with an intrinsic room temperature conductivity value of ≈0.4Sm−1. The n‐type walls showed non‐Ohmic behaviour and a significantly lower conductivity, supporting the prediction that electrons are in a polaronic state; an upper bound for the room temperature conductivity of the domains themselves is ≈6 × 10−6Sm−1 at 0.1 MVm−1.

中文翻译：

---

带电 ErMnO3 畴壁传导的基本方面

现在已经确定，铁电畴壁（极化不连续的地方）通常是导电的。然而，关于支撑电导率的物理学却缺乏相当基本的信息。在此，报告了基于开尔文探针力显微镜 (KPFM) 的实验，这些实验为有关 ErMnO 中畴壁的电荷传输提供了重要的新见解3。在一组实验中，KPFM 用于绘制在抛光单晶表面形成的霍尔电势的空间图。这些图提供了直接的实验证据n‐型头对头畴壁出现在其他情况下p‐型材料。在另一组实验中，通过切割亚微米厚的 ErMnO 层状切片来限制电流的几何形状3（使用聚焦​​离子束显微镜）。单独联系是为了n和p测量驱动源漏电流时的型壁和电势分布（再次使用 KPFM）。电流-电场函数显示出欧姆行为p‐型墙，固有室温电导率值为 ≈0.4Sm−1。这n-型壁表现出非欧姆行为和显着较低的电导率，支持电子处于极化状态的预测；域本身的室温电导率上限为 ≈6 × 10−6钐−10.1MVm 时−1。