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

The spin density in Co2FeGa Heusler alloy has been measured in a magnetic C ompton scattering experiment using 274-keV circularly polarized synchrotron radiation at the high energy inelastic scattering beamline (BL08W) at SPri ng-8, Japan. A detailed band-structure calculation including hyperfine fiel d study was performed utilizing the generalized gradient corrected full-pot ential linear augmented plane-wave (FLAPW-GGA) method. The magnetic Compton profiles for the [100], [110]. and [111] principal directions, reported he re, 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), w hich is at variance with the prediction of a positive moment from the recen t neutron data. In the calculation, 3d spin moment at the Co and Fe site wa s found to be 1.20 mu (B) and 2.66 mu (B), and their respective contributio n in the e(g) and t(2g) sub-bands are in excellent agreement with the earli er reported neutron-diffraction measurements. It is also seen from our calc ulated results that the Co and Fe moment are mainly e(g) in character.