Size Effects in the Nanoindentation of Bimetallic Ni-Au Nanowires
Erin Wood (University of Vermont), Trevor Avant (University of Vermont), Gil-Sung Kim (Department of Semiconductor Science and Technology, Chonbuk National University), Sang-Kwon Lee (Department of Physics, Chung-Ang University), John Hughes (Department of Geology, University of Vermont), Frederic Sansoz ( Mechanical Engineering Program, School of Engineering, University of Vermont)
Synthesis, Characterization, and Modeling of Low-Dimensional Nanomaterials
Wed 10:45 - 12:15
Salomon 202
Progress in nanoindentation has made possible a local analysis of mechanical behavior in metallic nanowires (NWs) that are important for devices. The crucial role of slip events from free surfaces in nanoscale plasticity is well-documented for low-dimensional metallic crystals; yet the effects of indentation size, sample diameter, and stacking fault energy on hardness and deformation mechanisms in indented metallic NWs remain elusive. This talk will present an atomic force microscopy nanoindentation study of indentation size effects (ISE) in bimetallic Ni-Au NWs ranging from 60 nm to 380 nm in diameter. Significant ISE and strong dependence of hardness on diameter were found in bimetallic NWs fabricated by electrodeposition and fixed on functionalized substrates. The theoretical length scale associated with the observed ISE is shown to correspond to the NW diameter. These results also show good agreement with the deformation mechanisms predicted by molecular dynamics simulations in Au and Ni NWs.