First-principle studies of Al–Ru intermetallic compounds

The structural properties, heat of formation, elastic properties, and electronic structures of six kinds of binary Al–Ru intermetallics were studied using first-principle calculations. The structural properties of these intermetallic compounds agree well with previously reported experimental data except that the computed equilibrium lattice parameters of the orthorhombic Al5Ru2 crystal (Cmcm) are significantly different from the experimental data reported by Mi et al. [Intermetallics 2003;11:643]. With increasing Ru concentration, the bulk modulus of Al–Ru intermetallics increases linearly. Most of the Al–Ru alloys considered are conductors, while the Al2Ru alloy is an indirect band gap semiconductor with a band gap of 0.168 eV.