Determination of the hyperfine parameters of a-FeSi2 by angle dependent Mössbauer spectroscopy on single crystals

The hyperfine parameters of the metallic disilicide phase a-FeSi2 at room temperature are determined with high accuracy by conversion electron Mössbauer spectroscopy measurements on a single crystal. It is found that there are two well defined iron environments with different electron densities (isomer shifts 0.202 and 0.257 mm/s, resp.) and different electric field gradients. Both quadrupole splittings are negative (-0.382 and -0.730 mm/s, resp.) and the site occupation for both sites is different.