MEMS-based mechanical characterization of core-shell silicon carbide nanowires for Harsh environmental nanomechanical elements

This research clarified mechanical properties of core-shell silicon carbide nanowires (C/S-SiCNWs) grown by a vapor-liquid-solid (VSL) technique, using newly developed Electrostatically Actuated NAnotensile Testing devices (EANATs). The C/S-SiCNWs consist of a crystalline cubic silicon carbide (3C-SiC) core with <;111> axis wrapped by an amorphous SiOx shell. The stress-strain relations for individual C/S-SiCNWs and 3C-SiCNWs without the SiOx shell have been successfully obtained from the nanotensile tests using EANATs. Young's modulus of the C/S-SiCNWs was 247.2 GPa whereas that of the 3C-SiCNWs showed a quite different value of 498 GPa on average. The tensile strengths for C/S- and 3C-SiCNWs also showed 7.0 GPa and 22.4 GPa on average, respectively, which are enough huge values as a structural material of MEMS/NEMS.