The Development of Nanoscale Characterisation of Beam-Sensitive Materials using cryo- and low-dose STEM

在过去的二十年里，电子显微镜的进步提供了新的手段，我们可以利用4D STEM来研究以前不可能在如此长的尺度上进行检查的各种“软”材料的纳米级结构。这主要是由探测器技术、计算能力和我们与显微镜接口的简易性的发展推动的。该项目以这些进展为基础，专注于优化采集策略，在不对样本造成重大损害的情况下最大限度地提高数据质量。该项目有许多明确的目标，包括设计一种新的中温冷柜以实现无冰、低剂量的低温STEM，实施和优化“智能”扫描与在线重建，以及更好地了解应用于软材料的临界剂量(和剂量率)。在这些技术发展的同时，还将研究一系列模型体系，包括药物、无机-有机杂化结构和聚合物。

Advances in electron microscopy over the past twenty years have provided new means by which we can investigate, using 4D STEM, the nanoscale structure of a vast range of 'soft' materials previously impossible to examine at such lengthscales. This has been driven primarily by developments in detector technology, computational power and the ease with which we can interface with the microscope. This project builds on these advances and focusses on optimising acquisition strategies to maximise data quality without significant damage to the sample. The project has a number of clear objectives including the design of a new intermediate temperature cold holder to enable ice-free low dose cryoSTEM, the implementation and optimisation of 'smart' scanning coupled with in-painting reconstructions and a greater understanding of the critical dose (and dose-rate) as applied to soft materials. Alongside these technical developments, a series of model systems will be studied including pharmaceuticals, hybrid inorganic-organic structures and polymers.