Nanoscale imaging of the full strain tensor of specific dislocations extracted from a bulk sample
Nanoscale imaging of the full strain tensor of specific dislocations extracted from a bulk sample
复制标题
DOI：
10.1103/physrevmaterials.4.013801
复制
发表时间：
2020-01-14
影响因子：
3.4
通讯作者：
Liu, Wenjun
中科院分区：
文献类型：
--
作者：
Hofmann, Felix;Phillips, Nicholas W.;Liu, Wenjun
晶格缺陷在决定晶体材料的性能方面起着关键作用。探索支配它们相互作用的三维（3D）晶格应变仍然是一个挑战。布拉格相干衍射成像（BCDI）允许以纳米级3D分辨率测量应变。然而，它目前仅限于形成微晶的材料。在这里，我们介绍了一种技术，允许从散装材料的BCDI样品的制造。以钨为例，我们表明聚焦离子束加工可用于从宏观晶体中提取含有特定预选缺陷的微米级BCDI样品。为了解释实验数据，我们开发了一个基于位移梯度的多次反射BCDI分析。这允许从包含多个位错的样品中精确地恢复全晶格应变张量。这些功能为BCDI作为研究复杂现实世界材料的显微镜工具打开了大门。
Lattice defects play a key role in determining the properties of crystalline materials. Probing the three-dimensional (3D) lattice strains that govern their interactions remains a challenge. Bragg coherent diffraction imaging (BCDI) allows strain to be measured with nanoscale 3D resolution. However, it is currently limited to materials that form microcrystals. Here we introduce a technique that allows the manufacture of BCDI samples from bulk materials. Using tungsten as an example, we show that focused ion-beam machining can be used to extract, from macroscopic crystals, micron-sized BCDI samples containing specific preselected defects. To interpret the experimental data, we develop a displacement-gradient-based analysis for multireflection BCDI. This allows accurate recovery of the full lattice strain tensor from samples containing multiple dislocations. These capabilities open the door to BCDI as a microscopy tool for studying complex real-world materials.