Dynamic Atomic Mechanisms of Plasticity of Ni Nanowires and Nano Crystalline Ultra-Thin Films

Abstract

Using our recently developed in situ transmission electron microscopy techniques, we revealed that the FCC structured Ni nanowires with diameter of about 30 nm possess ultra-large strain plasticity. Dynamic complex dislocation activities mediated the large strain bent-plasticity and they were monitored at atomic scale in real time. The bent-induced strain gradient allows studying the strain effects on dislocation mediated plasticity. We also explored the deformation techniques to more general cases, the nano thin films. An example of tensile Pt ultra-thin film is presented.

In situ experimental mechanics of nanomaterials at the atomic scale

“…With this method, Sun et al 27,35 investigated the deformation dynamics of NCs through the controlled irradiation of MWCNTs. Han et al 25,26,[36][37][38] developed an alternative TEM grid technique that can bend or conduct axial tensile experiments on individual NWs using a pre-broken colloidal thin film on the TEM grid. The above two methods do not require mechanical tensile attachments, and the specimen could be tilted along a pair of two orthogonal directions with large angles.…”

“…Based on the thermal bimetallic technique that has been used in SEM analyses, 28 Han et al 38 developed a novel in situ controllable tensile testing device for TEM measurements, which can slowly and gently deform the NWs, NTs, NPs and nanocrystalline thin films. Their method can even measure regular TEM samples assisted by focused ion-beam fabrication while retaining the double-tilt capability for performing high-resolution TEM (HRTEM) observations and regular 'two-beam' dark field imaging investigations.…”