Hyperfine magnetic field on iron atoms and Co-Fe disordering in Co₂FeSi

The Heusler compound Co2FeSi is a prospective half-metallic material for spintronic applications. Defects and antisite disordering play a crucial role among the factors reducing spin polarization in such materials. To clarify effects of possible off-stoichiometry, a continuous series of model solid solutions Co3-xFexSi (0.6 <= x <= 1.4) was investigated by Fe-57 Mossbauer spectroscopy and Co-59 nuclear magnetic resonance. It has been shown that the hyperfine magnetic fields on Fe can be used to monitor Co-Fe disordering in Co2FeSi-based bulk samples and thin films. (C) 2010 American Institute of Physics. [doi:10.1063/1.3352572