TY - JOUR
T1 - Electron beam induced artifacts during in situ TEM deformation of nanostructured metals
AU - Sarkar, Rohit
AU - Rentenberger, Christian
AU - Rajagopalan, Jagannathan
N1 - Funding Information:
This project was funded by the National Science Foundation (NSF) grants ECCS 1102201, CMMI 1400505 and DMR 1454109. The authors would like to gratefully acknowledge the use of facilities at the John M. Cowley Centre for High Resolution Electron Microscopy and the Centre for Solid State Electronics Research at Arizona State University and at the Faculty of Physics of the University of Vienna. Financial support from the Austrian Science Fund (FWF): [P22440, I1309] is acknowledged.
PY - 2015/11/10
Y1 - 2015/11/10
N2 - A critical assumption underlying in situ transmission electron microscopy studies is that the electron beam (e-beam) exposure does not fundamentally alter the intrinsic deformation behavior of the materials being probed. Here, we show that e-beam exposure causes increased dislocation activation and marked stress relaxation in aluminum and gold films spanning a range of thicknesses (80-400 nanometers) and grain sizes (50-220 nanometers). Furthermore, the e-beam induces anomalous sample necking, which unusually depends more on the e-beam diameter than intensity. Notably, the stress relaxation in both aluminum and gold occurs at beam energies well below their damage thresholds. More remarkably, the stress relaxation and/or sample necking is significantly more pronounced at lower accelerating voltages (120 kV versus 200 kV) in both the metals. These observations in aluminum and gold, two metals with highly dissimilar atomic weights and properties, indicate that e-beam exposure can cause anomalous behavior in a broad spectrum of nanostructured materials, and simultaneously suggest a strategy to minimize such artifacts.
AB - A critical assumption underlying in situ transmission electron microscopy studies is that the electron beam (e-beam) exposure does not fundamentally alter the intrinsic deformation behavior of the materials being probed. Here, we show that e-beam exposure causes increased dislocation activation and marked stress relaxation in aluminum and gold films spanning a range of thicknesses (80-400 nanometers) and grain sizes (50-220 nanometers). Furthermore, the e-beam induces anomalous sample necking, which unusually depends more on the e-beam diameter than intensity. Notably, the stress relaxation in both aluminum and gold occurs at beam energies well below their damage thresholds. More remarkably, the stress relaxation and/or sample necking is significantly more pronounced at lower accelerating voltages (120 kV versus 200 kV) in both the metals. These observations in aluminum and gold, two metals with highly dissimilar atomic weights and properties, indicate that e-beam exposure can cause anomalous behavior in a broad spectrum of nanostructured materials, and simultaneously suggest a strategy to minimize such artifacts.
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U2 - 10.1038/srep16345
DO - 10.1038/srep16345
M3 - Article
AN - SCOPUS:84947229799
SN - 2045-2322
VL - 5
JO - Scientific reports
JF - Scientific reports
M1 - 16345
ER -