DISORDER-INDUCED LOCAL MOMENT ENHANCEMENT IN COMPENSATED SI-P,B

The recently observed magnetic properties of the compensated Si:P,B an d uncompensated Si:P are discussed in the light of a statistical mean field approach to the disordered Hubbard Hamiltonian. Besides giving a n explanation for the observed enhancement of the local moment formati on in the compensated materials, the model predicts the correct behavi our for the susceptibility as a function of the impurity density. In a greement with the experimental findings a larger persistence of the ma gnetic properties at high density is expected for larger compensation values.