It is well-known that grain boundaries (GBs) increase the electrical resistivity of metals due to their enhanced electron scattering. The resistivity values of GBs are determined by their atomic structure; therefore, assessing the local resistivity of GBs is highly significant for understanding structure–property relationships. So far, the local electrical characterization of an individual GB has not received much attention, mainly due to the limited accuracy of the applied techniques, which were not sensitive enough to detect the subtle differences in electrical resistivity values of highly symmetric GBs. Here, we introduce a detailed methodology to probe in situ or ex situ the local resistivity of individual GBs in Cu, a metallic model system we choose due to its low resistance. Both bulk Cu samples and thin films are investigated, and different approaches to obtain reliable and accurate resistivity measurements are described, involving the van der Pauw technique for macroscopic measurements as well as two different four-point-probe techniques for local in situ measurements performed inside a scanning electron microscope. The in situ contacts are realized with needles accurately positioned by piezodriven micromanipulators. Resistivity results obtained on coincidence site lattice GBs (incoherent Σ3 and asymmetric Σ5) are reported and discussed. In addition, the key experimental details as well as pitfalls in the measurement of individual GB resistivity are addressed.

中文翻译：

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高灵敏度和空间分辨率的金属中晶界电阻率测量方法：以铜为例的研究。

众所周知，晶界（GBs）由于增强了的电子散射而增加了金属的电阻率。GBs的电阻率值取决于它们的原子结构。因此，评估GBs的局部电阻率对于理解结构-属性关系非常重要。到目前为止，单个GB的局部电特性并未受到太多关注，这主要是由于所应用技术的精确度有限，这些技术不够灵敏，无法检测到高度对称的GB电阻率值的细微差异。在这里，我们介绍一种详细的方法来进行原位或非原位探测Cu中单个GBs的局部电阻率，由于其低电阻，我们选择金属模型系统。研究了大量的铜样品和薄膜，并描述了获得可靠和准确的电阻率测量的不同方法，其中包括用于宏观测量的van der Pauw技术以及用于在内部进行局部原位测量的两种不同的四点探针技术扫描电子显微镜 在原位接触是通过压电驱动的微操纵器精确定位的针来实现的。报告并讨论了在重合点晶格GBs（非相干Σ3和非对称Σ5）上获得的电阻率结果。此外，还讨论了关键实验细节以及单个GB电阻率测量中的陷阱。