Magnetic susceptibility of diluted magnetic semiconductors

In this thesis we investigate the magnetic properties of (III,Mn)V diluted magnetic semiconductors in the low carrier concentration regime. Variational and perturbative methods are applied to an impurity-band model, in order to derive approximation schemes for computation of the dynamical and the static magnetic susceptibilities. Based on these, we carry out numerical simulations which allow us to investigate the effects of positional disorder of the Mn atoms on the magnetic properties of the system. The magnetic susceptibilities are shown to depend sensitively on the amount of positional disorder. The results we obtain are consistent with previous studies of the spin wave spectrum and of the inhomogeneous ferromagnetic state of these materials.Science, Faculty ofPhysics and Astronomy, Department ofGraduat