Energetic evaluation of the semiconducting mono-, sesqui-, and di-silicides of the 8th group elements (Fe, Ru and Os) using first-principle calculations

Energetic evaluation of the 8th group element (Fe, Ru and Os) mono-, sesqui-, and di-silicides has been performed using a first-principle calculation based on the density-functional theory. The following phases are expected to be present as equilibrium phases: FeSi, β-FeSi2, RuSi, α-Ru2Si3, Os2Si3, and OsSi2. RuSi2, which has been formed only as a metastable phase, was properly predicted to be unstable compared to the mixture of Ru2Si3 and Si. Hypothetical Fe2Si3 with the α-Ru2Si3-type structure was also predicted to be much more unstable than the mixture of FeSi and β-FeSi2. These are consistent with the observed facts.