Cluster characteristics and physical properties of binary Al-Zr intermetallic compounds from first principles studies

The cluster characteristics and physical properties of binary Al-Zr intermetallics have been studied in this work by performing first principles calculations. Our investigations indicate that there is a linear dependence between the mass density and Zr-content for these Al-Zr intermetallics. Besides, the coordination number of characteristic principal clusters corresponding to these Al-Zr crystalline phases varies from 10 to 16, and the local atomic structural characteristics of Al-Zr alloys can be properly reflected via the principal clusters. Results on formation energies and elastic constants reveal that these Al-Zr intermetallics are thermodynamically and mechanically stable, among which Al₂Zr possesses the largest elastic modulus and the highest hardness. Except for AlZr₂ and AlZr₃, the other Al-Zr intermetallics are brittle phases by comparison. Furthermore, studies on electric properties suggest that all of these Al-Zr intermetallics studied here are conductive phases.