Random iron-nickel alloys: From first principles to dynamic spin fluctuation theory

We provide a systematic analysis of finite-temperature magnetic properties of random alloys FexNi1-x with the face-centered-cubic structure over a broad concentration range x. By means of the spin-polarized relativistic Korringa-Kohn-Rostoker method we calculate the electronic structure of disordered iron-nickel alloys and discuss how a composition change affects magnetic moments of Fe and Ni and the density of states. We investigate how the Curie temperature depends on Fe concentration using conventional approaches, such as mean-field approximation or Monte Carlo simulations, and dynamic spin-fluctuation theory. Being devised to account for spin fluctuations explicitly, the latter method shows the best fit to experimental results.

Automated summary

We systematically analyzed the finite-temperature magnetic properties of random alloys FexNi1-x with the face-centered-cubic structure across a wide range of concentrations. Utilizing the spin-polarized relativistic Korringa-Kohn-Rostoker method, we calculated the electronic structure of disordered iron-nickel alloys and explored how changes in composition affect magnetic moments and density of states. We investigated the dependence of the Curie temperature on Fe concentration using various techniques, with the dynamic spin-fluctuation theory showing the best fit to experimental results by explicitly accounting for spin fluctuations.