Phase Stability and Mechanical Properties of Al8Fe4RE via First-Principle Calculations

Abstract

We report on the phase stability, elastic, electronic, and lattice dynamic properties of 17 Al8Fe4RE (RE = Sc, Y, La–Lu) intermetallic compounds (IMCs) using first-principle calculations. The calculated lattice constants coincided with the experimental results. The calculated enthalpy formation indicated that all the 17 IMCs are stable. The elastic constants and various moduli indicated that Al8Fe4RE can be used as a strengthening phase due to its high Young’s modulus and shear modulus. The 3D surfaces of Young’s modulus for Al8Fe4RE showed anisotropic behavior, and the values of hardness for the IMCs were high (about 14 GPa). The phonon spectra showed that only Al8Fe4Y had a soft mode, which means the other IMCs are all dynamically stable.