Aplicações, metodologia e propriedades físicas do método do átomo embebido para elementos FCC

Abstract

The purpose of this work is to present a method called Embedded Atom Method (EAM), in which the energy of a system of particles grouped in a solid solution or metallic alloys is obtained. Based on calculations ab initio and density functional theory (DFT), EAM was originally developed by MIBaskes in the middle of 1980 and gradually adapted according to the lines of research of several researchers in the area of Condensed Matter Physics. Due to its computational feasibility, the EAM method has been widely applied in the fields of Computational Physics and Chemistry, where, by simulations, it has been shown to be quite effective when compared to the experimental values. However, the EAM is based on curve fittings, parameter adjustments and certain approximations, which together give rise to some imprecisions and weaknesses in the method. Such inaccuracies are mainly related to the approximation that is made to the electronic densities at a given site of the solid. In this case, the electronic densities are approximated by a linear superposition of electron densities with spherical symmetries, that is, only the contributions of the s orbital are considered, a fact that does not correspond to the real solid model. Realizing this weakness, Baskes modified his EAM method by adding the angular dependencies of electronic densities, this time considering the symmetries of the p, d and f orbitals . Because of this modification, the EAM has been called the Modified Embedded Atom Method (MEAM).