关键词: first principle calculations, Fermi surface, elastic moduli, entropy, and internal energy, optical properties

Abstract: The electronic properties (Fermi surface, band structure, and density of states (DOS)) of Al-based alloys AlM₃ (M=Zr and Cu) and AlCu₂Zr are investigated using the first-principles pseudopotential plane wave method within the generalized gradient approximation (GGA). The structural parameters and elastic constants are evaluated and compared with other available data. Also, the pressure dependences of mechanical properties of the compounds are studied. The temperature dependence of adiabatic bulk modulus, Debye temperature, specific heat, thermal expansion coefficient, entropy, and internal energy are all obtained for the first time through quasi-harmonic Debye model with phononic effects for T=0 K-100 K. The parameters of optical properties (dielectric functions, refractive index, extinction coefficient, absorption spectrum, conductivity, energy-loss spectrum, and reflectivity) of the compounds are calculated and discussed for the first time. The reflectivities of the materials are quite high in the IR-visible-UV region up to ~15 eV, showing that they promise to be good coating materials to avoid solar heating. Some of the properties are also compared with those of the Al-based Ni₃Al compound.

Key words: first principle calculations, Fermi surface, elastic moduli, entropy, and internal energy, optical properties