Spin-polarized itinerant electrons in Co-based Heusler compounds investigated by magnetic Compton scattering

The spin-polarized electron momentum density distributions (magnetic Compton profiles) of Co2YAl (Y = Ti, V, Cr, and Fe) Heusler compounds have been measured using a magnetic Compton scattering technique. The experimental magnetic Compton profiles have been decomposed into the itinerant electron and localized 3d electron contributions. The decomposition shows that the number of spin-polarized itinerant electrons is proportional to that of spin-polarized localized 3d electrons, indicating that the strength of indirect exchange interaction is dominated by the localized 3d magnetic moment. This finding suggests that the spin-polarized itinerant part in the magnetic Compton profile is used as a scale that can measure the strength of the sp-d interaction.