Atomic-scale observation of the deformation and failure of diamonds by in-situ double-tilt mechanical testing transmission electron microscope holder

Abstract

In-situ transmission electron microscopy (TEM) has been demonstrated to be a powerful method in resolving challenging problems such as interactions among various defects. To take advantage of the atomic resolution of advanced TEMs, a compact five-degree-of-freedom nanomanipulator was integrated with an indenter that was made of nanotwinned diamonds, for both the in-situ mechanical testing and double tilting of TEM samples. As a demonstration, in-situ bending tests were performed on the (111), (110) and (100) single-crystal diamond needles. The tests revealed the {111} cleavage to be the dominant failure mode. The in-situ indentation on a diamond nanoplate led to curved cracks consisting of nanometer-scale steps, which were identified to be atomic flat {111} facets. The atomic-scale observation of the deformation and failure of diamonds demonstrated the stability of the entire system and the durability of the indenter. We expect that more delicate research can be carried out by means of this holder in the near future, including in-situ stimulation, atomic characterization, and tomography.