Electron localization analysis for a macroscopic property indicator in the disordered FCC solid solution of compositionally complex alloys

Structural properties of alloys, including strength, ductility, and hardness are important for informing engineers of appropriate alloy selection in applications ranging from household appliances to citywide infrastructure. Our group's previous experimental results have indicated that changes in atomic percentage as small as ~5% in the chemical composition caused variation in overall present phases, hardness, yield strength and ductility. This work utilizes the electron localization function calculated from density functional theory to explore the hypothesis that a disordered FCC solid solution contains regions of strong electron localization, correlated with an increase in hardness, yield strength and decrease in ductility, when larger concentrations of Al and Zn are present in a Cu-Mn-Ni matrix. Representative FCC crystal cells were constructed through the generation of special quasirandom structures with both chemical disordering and ferromagnetic and antiferromagnetic contributions of Ni and Mn taken into consideration. This work focuses on the analysis of this FCC phase in the various compositional arrays and discusses future probing of other metallic phases via the electron localization function for interesting regions of electron localization and delocalization for various compositions.