Electrical resistivity is the key parameter in the active regions of many current nanoscale devices, from memristors to resistive random-access memory and phase-change memories. The local resistivity of the materials is engineered on the nanoscale to fit the performance requirements. Phase-change memories, for example, rely on materials whose electrical resistance increases dramatically with a change from a crystalline to an amorphous phase. Electrical characterization methods have been developed to measure the response of individual devices, but they cannot map the local resistance across the active area. Here, we propose a method based on operando electron holography to determine the local resistance within working devices. Upon switching the device, we show that electrical resistance is inhomogeneous on the scale of only a few nanometers.

中文翻译：

---

测量纳米级相变材料的电阻率


电阻率是许多当前纳米级器件（从忆阻器到电阻式随机存取存储器和相变存储器）有源区域的关键参数。材料的局部电阻率在纳米级上进行设计，以满足性能要求。例如，相变存储器所依赖的材料的电阻随着从结晶相变为非晶相的变化而急剧增加。电气表征方法已被开发用于测量单个器件的响应，但它们无法绘制整个有源区域的局部电阻。在这里，我们提出了一种基于操作电子全息术的方法来确定工作设备内的局部电阻。切换设备后，我们发现电阻在仅几纳米的范围内是不均匀的。