Charge and spin density perturbation on iron atom due to osmium impurity in metallic iron

Samples of natural α-Fe doped randomly with Os impurities up to about 9 at.% have been investigated by means of the 14.41 keV Moessbauer absorption spectroscopy of 57Fe vs. Os concentration at room temperature. It has been found that the nearest neighbour single Os impurity decreases this field by 1.11 T. More distant impurities slightly increase iron hyperfine iron hyperfine field. There are no discernible effects of the Os-Os interaction on the magnetic field seen by iron. On the other hand, the electron charge density on the iron nucleus is increased by the nearest neighbour Os atom as seen via changes in the isomer shift, i.e. via changes in the spectral shifts. The second neighbour impurity has the opposite effect on the charge density. More distant impurities tend to decrease the charge density as well. The effect of the first and second neighbour impurities decreases with increasing overall Os concentration indicating some Os-Os interaction influencing a charge density of the conduction electrons seen on the iron nucleus. (author)