Mesoscopic electric field predictions and specimen shape measurements to improve reconstruction in atom probe tomography

原子探针层析成像是一种显微镜和微区分析技术，它可以以近原子的精度绘制出材料中小体积中每种元素的分布。伦敦帝国理工学院正在建立一个新的设施，以便在受控气氛下将样品从原子探针转移到透射电子显微镜中，从而对原子探针样品进行精确成像，这些样品的直径小于100纳米。在分析复杂的设备，通常是多层堆叠，样品可以开发影响数据重建的空间精度的复杂形状。该项目将建立在与牛津大学合作的基础上，进行中断的原子探针实验，通过电子显微镜获取样品形状，并将其输入介观模型，以改进重建协议，并将结构组成和活性与能源应用材料相关联。我们将结合联合收割机这些模型与实验测量的样品形状的薄膜材料的能源应用，成像透射电子显微镜在不同阶段的分析。开发的模型没有与CAMECA提供的仪器连接或嵌入，因此它不会为CAMECA提供竞争优势，因为它主要用于学术用途。

Atom probe tomography is a microscopy and microanalysis technique that can map the distribution of each element in small volume of a material with near-atomic precision. A new facility at Imperial College London is being set up to allow for facile transfer, under controlled atmosphere, of specimens from the atom probe into a transmission electron microscope, allowing for precise imaging of atom probe specimens, which sharp needles below 100 nanometres across. In the analysis of complex devices, typically multilayer stacks, the specimen can develop complex shapes that affect the spatial precision of the data reconstruction. This project will build on a collaboration with the University of Oxford to perform both interrupted atom probe experiments to acquire specimen shapes by electron microscopy and feed these into a mesoscopic model to improve reconstruction protocols, and correlate structure-composition and activity on materials for energy application. We will combine these models with experimental measurements of specimen shape on thin films of materials for energy applications, imaged by transmission-electron microscopy at different stages of the analysis. The developed model is not linked or embedded with the instrument provided by CAMECA, so it will not provide a competitive advance to CAMECA as this is mostly for academic use.