Theory of relativistic photoemission for correlated magnetic alloys: LSDA plus DMFT study of the electronic structure of NixPd1-x

Electronic correlations play an important role in determining the properties of solid state systems, in particular, in the presence of narrow bands. In intermetallic alloys the strength of correlation effects and, thus, the details of the electronic structure depend on the concentration of the constituents, their interactions, and the degree of chemical order. Although the electronic structure of such a system can be conveniently studied by photoelectron spectroscopy, the interpretation of the spectra is nontrivial. To enable a quantitative analysis of chemically disordered systems showing correlation effects in photoemission spectroscopy we therefore incorporate dynamical mean-field theory in the fully relativistic version of layer-Korringa-Kohn-Rostoker theory and treat the results within the relativistic one-step model of photoemission generalized to the magnetic alloy case. Our ansatz allows the study of complex layered structures like thin films and multilayers and an almost naturally incorporation of a realistic surface barrier potential. We apply our theory to photoemission data of the magnetic alloy system NixPd1-x(001) and demonstrating that state-of-the-art photoemission theory is required to deal with this complex system. The comparison over a large alloy concentration range provides us with a means to disentangle the influence of alloying and correlation effects.