Reconstruction of the uncompensated electron momentum density distribution by the maximum entropy method

The application of the maximum entropy method (MEM) to the reconstruction of the three-dimensional electron momentum density for electrons with uncompensated spins is described. The case of iron, for which the largest collection of experimental data is available, is presented in detail. The analysis of the distributions in Fe sub 3 Si and Cu sub 2 MnAl alloys is carried out based on measurements of the magnetic Compton profiles along only three high-symmetry crystallographic directions. It is shown that the general density distributions in Fe and Fe sub 3 Si are very much alike, while the data for Cu sub 2 MnAl can be interpreted with a single strictly positive distribution. It is postulated that the crater-like structure of the magnetic Compton profiles may be due to both conduction and d-band polarizations. In such a case one could reconcile the results of the neutron and Compton experiments.