Nanoscale twinning-induced elastic strengthening in silicon carbide nanowires

Compressibility of periodically twinned silicon carbide nanowires is studied using in situ high pressure X-ray diffraction. Twinned SiC nanowires displayed a bulk modulus of 316 GPa, similar to 20-40% higher than previously reported values for SiC of other morphologies. This finding provides direct evidence of a significant effect of twinned structures on the elastic properties of SiC on the nano scale and supports previous molecular dynamics simulations of twin boundary/stacking fault-induced strengthening. Both experiments and simulations indicate that nanoscale twinning is an effective pathway by which to tailor the mechanical properties of nanostructures. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.