|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale III
||W-28: Beam Induced Artifacts during in situ Transmission Electron Microscopy Deformation of Nanocrystalline and Ultrafine-grained Metals
||Rohit Sarkar, Christian Rentenberger, Jagannathan Rajagopalan
|On-Site Speaker (Planned)
In situ transmission electron microscopy (TEM) is a powerful technique to elucidate deformation processes in nanostructured materials. A critical assumption in this technique is that the electron beam (e-beam) exposure does not fundamentally alter the materials’ intrinsic deformation mechanisms. Here, by systematically varying the beam conditions we show that e-beam exposure causes increased defect activation and marked stress relaxation in aluminum and gold films spanning a range of thicknesses (80-400 nm) and grain sizes (50-220 nm). Beam-induced artifacts increase with e-beam intensity but, contrary to expectation, the artifacts are more pronounced at lower accelerating voltages. Furthermore, e-beam exposure induces anomalous sample necking, which unusually depends on the beam diameter rather than intensity. These observations in two metals with highly dissimilar atomic weights and properties indicate that a broad spectrum of nanostructured metals are susceptible to beam-induced artifacts, and simultaneously point to a strategy to minimize such artifacts.
||Planned: A print-only volume