The structure and local surrounding of Fe in Co2-xFe1+xSi.

This work reports on the magnetostructural properties of Co2-xFe1+xSi with 0<x<1. The Heusler compound Co2FeSi is a half-metallic ferromagnet with high Curie temperature and was suggested as candidate for a high tunneling magnetoresistance. Changing the Fe content allows to tune its magnetic properties. It is demonstrated that the solid solution series Co2-xFe1+xSi is perfectly ordered. 57Fe Mössbauer spectroscopy was used to determine the local hyperfine magnetic fields of the Fe atoms. Two different hyperfine magnetic fields are detected in samples with x>0. Changes in the relative intensities indicate the well ordered substitution of Co by Fe atoms [ABSTRACT FROM AUTHOR]