ELECTRONIC AND STRUCTURAL-PROPERTIES OF CU-AU ALLOYS

The electronic and structural properties of random Cu-Au alloys have b een determined using the (all-electron) fully relativistic Korringa-Ko hn-Rostoker coherent potential approximation. The concentration was va ried in steps of 10% (5% for the A3B and AB3 compositions) and total e nergy calculations were carried out to determine the corresponding equ ilibrium lattice constants. Just like the experimental data from which they differ at most by 1.5%, the calculated equilibrium lattice const ants show a positive deviation from Vegard's law. The calculated heat of mixing agrees well with the existing experimental data. The equilib rium spectral properties of random Cu-Au alloys are discussed in terms of theoretical photoemission spectra and are compared to experimental data for Cu3Au and pure Au. The structural properties of the composit ional series are presented using lattice-constant- and concentration-d ependent effective pair (and triplet) interactions up to fourth (tenth ) -nearest neighbors and related quantities such as ordering energies and antiphase boundary energies. The ordering processes that govern th e CU3Au and CuAu structure are discussed.