Synergy between material, surface science experiments and simulations

Abstract

This chapter examines the link between bulk alloys and surfaces and the necessary conditions that effective simulation techniques must meet in order to properly describe, in a consistent manner, the varied phenomena that characterize each field of research. After a brief description of the thermodynamics of alloy formation and surface segregation in ordered and disordered alloys, model calculations combining the Monte Carlo method and suitable energy models are presented as fully complementary to experiments in order to gain insight in segregation and other surface phenomena, deployed by materials in order to minimize their surface free energy and hence their total Gibbs free energy. In the confrontation between experiments and modeling, it is assumed that the surface, as observed experimentally, corresponds to the equilibrium situation of minimal Gibbs free energy. The entropy part is modeled by the stochastic nature of Monte Carlo simulations, while the energy part is taken into account by appropriate energy models. In this chapter, we describe the (modified) embedded atom method, the derivation of its parameters, and its applications to several cases of interest.