Effect of ellipsodial fermi surfaces and relaxation processes on the indirect exchange in the Bloembergen-Rowland approximation

We investigate the effect of relaxation processes (mean free path) and ellipsodial Fermi surfaces on the indirect exchange interaction in the Bloembergen-Rowland approximation and obtain a simple analytic expression which oscillates with mean free path and emphasizes the relative importance of this parameter on the oscillatory behaviour of the indirect exchange.