3D Volume Microscopy and TEM Sample Preparation of Complex Hybrid Nanostructures

在用于固体的连续离子束切片的双束分析扫描电子显微镜（SEM）中使用聚焦离子束（FIB）允许以大于使用X射线显微断层摄影可实现的分辨率的分辨率研究数百立方微米体积上的三维（3D）化学微米和纳米结构，所谓的3D体积显微镜。此外，还可以提取特定位置的薄透射电子显微镜（TEM）横截面，用于微观结构内表面或界面的更高分辨率分析。液氮冷却的样品低温台的使用减少了离子束损伤，并允许应用于对束敏感的样品，例如混合无机-有机材料、有机物以及冷冻样品，否则这是非常具有挑战性的。此外，包含冷却的纳米操纵器和扫描TEM（STEM）检测器使得能够对冷冻的TEM薄片进行原位成像，原则上，冷冻的TEM薄片可以冷冻转移到外部冷冻TEM以进行额外的分析。除了减少传统无机材料的损坏外，这种能力还为在广泛的医疗、化学、结构和电子应用中使用的复杂软固体（和潜在的液体分散体）的表征开辟了新的视野。

Use of a focused ion beam (FIB) in a dual beam, analytical scanning electron microscope (SEM) for serial ion beam sectioning of solids allows the investigation of the three dimensional (3D) chemical micro- and nanostructure over volumes of hundreds of cubic microns, so called 3D volume microscopy, at resolutions greater than that achievable using X-ray microtomography. In addition, it is possible to extract site-specific thin transmission electron microscopy (TEM) cross-sections for the higher resolution analysis of surfaces or interfaces within the microstructure. The use of a liquid nitrogen-cooled sample cryo-stage reduces ion beam damage and permits the application to beam-sensitive samples such as hybrid inorganic-organic materials, organics and also frozen samples which is otherwise extremely challenging. Furthermore, the inclusion of a cooled nanomanipulator and a scanning TEM (STEM) detector enables in-situ imaging of frozen TEM lamella that, in principle, could be cryo-transferred to an external cryo-TEM for additional analysis. As well as reducing damage in conventional inorganic materials, such a capability opens up new horizons for the characterisation of complex soft solids (and potentially liquid dispersions) used in a wide range of medical, chemical, structural and electronic applications.