The anti-site was found to be the major defect on the Al-rich side of the RuAl single-phase field. The effect of the anti-site defect upon the lattice parameter within this composition range was calculated to be 0.0001415nm/at%. The atomic volume difference between Ru and Al atom was an important factor governing the defect structure.

Investigation of Point Defect Structure in Single Phase B2-Type RuAl Alloys by Lattice Parameter Measurements. H.A.Gobran, K.W.Liu, D.Heger, F.Mücklich: Scripta Materialia, 2003, 49[11], 1097-102