Planar Defects and Dislocations in C40 and FCC Lattices

Abstract

Atomic planes at three different positions ABC form the stacking along the <111> directions in the FCC lattice and similarly along the <0001> hexagonal axis in the C40 structure in transition metal silicides. However, the structures of silicides are constituted of several stacking of identical atomic planes at four different positions: AB in C11bstructures of e.g. MoSi2, ABC in C40 structures of e.g. VSi2and ABDC in C54 structures of e.g. TiSi2disilicides. The occurrence of the fourth position essentially influences the properties of defects and consequently the mechanical properties of C40 materials.