Magnetic Compton scattering study of the Co2FeGa Heusler alloy:: Experiment and theory -: art. no. 064409

The spin density in Co2FeGa Heusler alloy has been measured in a magnetic Compton scattering experiment using 274-keV circularly polarized synchrotron radiation at the high energy inelastic scattering beamline (BL08W) at SPring-8, Japan. A detailed band-structure calculation including hyperfine field study was performed utilizing the generalized gradient corrected full-potential linear augmented plane-wave (FLAPW-GGA) method. The magnetic Compton profiles for the [100], [110]. and [111] principal directions, reported here, show anisotropy in the momentum density which is in good agreement with the FLAPW-GGA results based on ferromagnetic ground state. The conduction electrons were found to have a negative spin polarization of 0.60 mu (B), which is at variance with the prediction of a positive moment from the recent neutron data. In the calculation, 3d spin moment at the Co and Fe site was found to be 1.20 mu (B) and 2.66 mu (B), and their respective contribution in the e(g) and t(2g) sub-bands are in excellent agreement with the earlier reported neutron-diffraction measurements. It is also seen from our calculated results that the Co and Fe moment are mainly e(g) in character.