Dislocation Dissociations and Dislocation Mobility in Diamond Lattice Crystals

Abstract

Dislocationdissociations are derived for AB‐type dislocations in the diamond lattice which slip on {111}, {001}, {110}, and {113} planes with stacking faults on planes of the 〈11̄0〉 and 〈112̄〉 zones. Atomic shuffling, necessary for the Shockley dissociation as atom pairs rotate to form the intrinsic twin stacking fault on {111}, is not required for nonplanar dissociations when type IIφ faults develop by rotation of one atomic bond through φ° while maintaining the closest atomic approach and coordination number. The nonplanar dissociations apply to all tetrahedrally coordinated layer structures, and are described for the iceI wurtzite structure, which shows similar plastic flow behavior as that in Ge and Si. Activation energies are evaluated for motion of dissociated dislocations and dissociated kinks and compared with existing data for dislocation velocities and internal friction effects. The effects of doping with donor and acceptor elements on the mobility of dissociated dislocations is found to be consistent with common‐ion and elastic modulus effects. The partialized dislocations give a consistent description of various phenomena, many of which cannot be explained by the Peierls barrier model.