Calculation of lattice defects in structural intermetallics by first-principles tight binding approach

An electronic theory for the total energy of transition-metal-polyvalent-metal binary alloys is developed using the generalized recursion method and the local-density-functional theory. This approach allows us to calculate the formation energy and the atomic structure of various lattice defects (point defects, planar defects, grain boundary and dislocations) in the intermetallic compounds like Ni3Al, NiAl and TiAl. The fundamental properties of various lattice defects in the ordered alloys are investigated in conjunction with their mechanical and thermodynamical properties.