Dislocation glide-controlled room-temperature plasticity in 6H-SiC single crystals

S Kiani and KWK Leung and V Radmilovic and AM Minor and JM Yang and DH Warner and S Kodambaka, ACTA MATERIALIA, 80, 400-406 (2014).

DOI: 10.1016/j.actamat.2014.07.066

In situ transmission electron microscopy observations of uniaxial compression of sub-300 nm diameter, cylindrical, single-crystalline 6H- SiC pillars oriented along < 0001 > and at 45 with respect to < 0001 > reveal that plastic slip occurs at room-temperature on the basal 0001 planes at stresses above 7.8 GPa. Using a combination of aberration- corrected electron microscopy, molecular dynamics simulations and density functional theory calculations, we attribute the observed phenomenon to basal slip on the shuffle set along < 1 (1) over bar 00 >. By comparing the experimentally measured yield stresses with the calculated values required for dislocation nucleation, we suggest that room-temperature plastic deformation in 6H-SiC crystals is controlled by glide rather than nucleation of dislocations. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Return to Publications page