We characterized the elastic properties of GaN nanowires grown along different crystallographic orientations. In situ transmission electron microscopy tensile tests were conducted using a MEMS-based nanoscale testing system. Complementary atomistic simulations were performed using density functional theory and molecular dynamics. Our work establishes that elasticity size dependence is limited to nanowires with diameters smaller than 20 nm. For larger diameters, the elastic modulus converges to the bulk values of 300 GPa for c-axis and 267 GPa for a- and m-axis.
Citation: Nano Letters
Pub Type: Journals
Gallium nitride nanowires, nanowire elastic modulus, in situ testing, first-principles calculations, molecular dynamics, size effect, surface reconstruction