Dislocations in materials with mixed covalent and metallic bonding
D. Nguyen-Manh, M. J. Cawkwell, R. Gröger, M. Mrovec, R. Porizek, D. G. Pettifor, V. Vitek.
Materials Science and Engineering: A-Structural Materials Properties Microstructure and Processing, 400-401, 68-71, (2005)
Environment-dependent bond-order potentials have been developed for Ll(0) TiAl, bcc Mo and fee In They comprise both the angular character of bonding and the screening effect of nearly free electrons. These potentials have been employed in atomistic studies of screw dislocations that revealed the non-planar character of their cores. It is argued that both covalent as well as metallic character of bonding govern these structures, which in turn control the mechanical behaviour.
Keyword(s): Core structure; Non-planar spreading; Screw dislocation; -Surface energies; Tight-binding scheme; Environmental dependence; Bond-order potentials