The electronic structure of a Cu impurity in Al

Abstract

The local density of states of a Cu impurity atom in Al is calculated using the matching Green function method. The Green function of the Cu atom is found from atomic wavefunctions and this is used with the Green function for bulk Al to find the Green function and local density of states of the impurity system. Inside the Cu atomic cell the local density of states is very different from the bulk value, with the formation of a virtual bound state about 0.6 eV wide, but the charge density is very similar. In the surrounding Al the local density of states and charge density go quite quickly to the bulk values. The reasons for the small energy of solution of Cu in Al are discussed.