Binary systems (Metallurgy)

The embedded cluster Monte Carlo (ECMC) method which combines the Korringa-Kohn-Rostoker coherent potential approximation embedded cluster method (KKR-CPA-ECM) and the Monte Carlo method has been developed in order to study phase diagrams of binary alloys. The KKR-CPA-ECM provides interchange energies to the Monte Carlo code. In this thesis, a pair-interaction (PI) method is used to provide interchange energies to the Monte Carlo code. The code of the PI method is obtained based on the KKR-CPA-ECM code. The interchange energies of Cu0.5 Zn0.5 alloys are calculated with the PI method. The critical temperature and the phase boundary of Cu-Zn alloys are obtained by carrying out both Monte Carlo calculations with above interchange energies and the ECMC calculations. A comparison between the results of both methods is made.

Computer simulations of the growth of binary alloy thin films in two and three dimensions were performed using an extension of the Solid on Solid model. Snapshots for a range of interactions and diffusion rates are presented and critically compared to experiment. A wide variety of distinct phases is identified and their growth conditions analyzed. These findings are summarized in a phase diagram. In addition, a fractal analysis of the domains is performed. It is found that for negative interactions the islands are two-dimensional, while for positive interactions, regardless of diffusion rate, a fractal dimension of 1.78 is obtained.