Third order corrections and finite conduction band effects on the indirect exchange interaction in the Bloembergen-Rowland approximation

We have investigated third order corrections and finite conduction band effects on the indirect exchange interaction assuming a large energy gap compared to the valence band width. We regain an oscillatory expression in which as opposed to the Bloembergen-Rowland formula the energy gap as well as the conduction band width modifies both the magnitude and phase of the oscillations.