Nanoscale twinning-induced elastic strengthening in silicon carbide nanowires

Received 30 June 2010; received in revised form 19 July 2010; accepted 20 July 2010. published online 26 July 2010.

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 316GPa, ∼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.

Keywords: Nano-twin, High pressure, Synchrotron, Silicon carbide

a Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, NM 87545, USA

b HPSynC, Carnegie Institution of Washington, 9700 South Cass Avenue, Argonne, IL 60439, USA

c State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People’s Republic of China

d State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Taiyuan 030001, People’s Republic of China

Corresponding author. Tel.: +1 505 664 0213; fax: +1 505 665 2676.

Corresponding author.

PII: S1359-6462(10)00496-3

doi:10.1016/j.scriptamat.2010.07.023

9 of 22