HOLLOW SCREW DISLOCATION CORES IN SILICON CARBIDE

Hollow screw dislocation cores have been observed in boron and nitrogen doped SiC. Their diameter, D, approximately obeys the theoretical relation1: [formula omitted] where μ is the modulus of rigidity, γ is the surface tension and b is the magnitude of the Burgers' vector. The evidence gives a possible range of γ from 20 • 10-13 to 100 • 10~13 erg per molecule, or 28.9 to 144 kcal per mole. The range is greater than the error of measurement and may reflect, among other things, a real dependence of γ on the type of dopant present. © 1969, Walter de Gruyter. All rights reserved.