Clark Trevor, Taylor Caitlin A, Barr Christopher M, Hattar Khalid
Sandia National Laboratories.
Sandia National Laboratories; Los Alamos National Laboratory.
J Vis Exp. 2022 Jun 27(184). doi: 10.3791/61293.
There is a need to understand materials exposed to overlapping extreme environments such as high temperature, radiation, or mechanical stress. When these stressors are combined there may be synergistic effects that enable unique microstructural evolution mechanisms to activate. Understanding of these mechanisms is necessary for the input and refinement of predictive models and critical for engineering of next generation materials. The basic physics and underlying mechanisms require advanced tools to be investigated. The in situ ion irradiation transmission electron microscope (I³TEM) is designed to explore these principles. To quantitatively probe the complex dynamic interactions in materials, careful preparation of samples and consideration of experimental design is required. Particular handling or preparation of samples can easily introduce damage or features that obfuscate the measurements. There is no one correct way to prepare a sample; however, many mistakes can be made. The most common errors and things to consider are highlighted within. The I³TEM has many adjustable variables and a large potential experimental space, therefore it is best to design experiments with a specific scientific question or questions in mind. Experiments have been performed on large number of sample geometries, material classes, and with many irradiation conditions. The following are a subset of examples that demonstrate unique in situ capabilities utilizing the ITEM. Au nanoparticles prepared by drop casting have been used to investigate the effects of single ion strikes. Au thin films have been used in studies on the effects of multibeam irradiation on microstructure evolution. Zr films have been exposed to irradiation and mechanical tension to examine creep. Ag nanopillars were subjected to simultaneous high temperature, mechanical compression, and ion irradiation to study irradiation induced creep as well. These results impact fields including: structural materials, nuclear energy, energy storage, catalysis, and microelectronics in space environments.
有必要了解暴露于高温、辐射或机械应力等重叠极端环境下的材料。当这些压力源组合在一起时，可能会产生协同效应，从而激活独特的微观结构演变机制。了解这些机制对于预测模型的输入和完善是必要的，对于下一代材料的工程设计至关重要。基本物理原理和潜在机制需要先进工具来进行研究。原位离子辐照透射电子显微镜（I³TEM）旨在探索这些原理。为了定量探测材料中复杂的动态相互作用，需要仔细制备样品并考虑实验设计。对样品进行特殊处理或制备很容易引入损伤或特征，从而模糊测量结果。制备样品没有一种正确的方法；然而，可能会犯很多错误。文中重点强调了最常见的错误及需要考虑的事项。I³TEM有许多可调节变量和很大的潜在实验空间，因此最好在设计实验时心中有一个或几个特定的科学问题。已经对大量样品几何形状、材料类别以及许多辐照条件进行了实验。以下是一些示例子集，展示了利用I³TEM的独特原位功能。通过滴铸法制备的金纳米颗粒已用于研究单离子撞击的影响。金薄膜已用于多束辐照对微观结构演变影响的研究。锆薄膜已接受辐照和机械拉伸以检查蠕变。银纳米柱同时受到高温、机械压缩和离子辐照，也是为了研究辐照诱导的蠕变。这些结果影响的领域包括：结构材料、核能、储能、催化以及空间环境中的微电子学。
