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

在过去的二十年里，电子显微镜的进步为我们提供了新的手段，通过4D STEM，我们可以研究大量“软”材料的纳米级结构，这些材料以前不可能在这样的长度尺度上进行检查。这主要是由探测器技术的发展、计算能力的提高以及我们可以轻松地与显微镜进行交互所推动的。该项目建立在这些进步的基础上，重点是优化采集策略，以最大限度地提高数据质量，而不会对样本造成重大损害。该项目有许多明确的目标，包括设计一种新的中温冷架，以实现无冰低剂量的cryoSTEM，实施和优化“智能”扫描，结合喷漆重建，以及更好地了解适用于软材料的临界剂量（和剂量率）。随着这些技术的发展，一系列的模型系统将被研究，包括药物，无机-有机混合结构和聚合物。

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.