Nanoscale imaging of the full strain tensor of specific dislocations extracted from a bulk sample

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.