Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of nanowires

Nanowires (NWs) exhibit size-dependent mechanical properties due to the high surface/volume ratio, in which temperature also plays an important role. The surface eigenstress model is further developed here to quantitatively predict the size-dependent mechanical properties of NWs and results in analytic formulas. Molecular dynamics (MD) simulations are conducted to study the size-dependent mechanical of [100], [110] and [111] Ni and Si nanowires within the temperature range of 100-400 K and the MD results verify perfectly the newly developed surface eigenstress model.