NUKLEONIKA 2004, 49(Supplement 3):s67-s70

CHARGE AND SPIN DENSITY PERTURBATION ON IRON ATOM DUE TO OSMIUM IMPURITY IN METALLIC IRON

Artur Błachowski1, Krzysztof Ruebenbauer1, Jan Żukrowski2

1 Mössbauer Spectroscopy Division, Institute of Physics, Pedagogical University, 2 Podchorążych Str., 30-084 Kraków, Poland,
2 Solid State Physics Department, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30 A. Mickiewicza Ave., 30-059 Kraków, Poland

Samples of natural a-Fe doped randomly with Os impurities up to about 9 at.% have been investigated by means of the 14.41 keV Mössbauer absorption spectroscopy of 57Fe vs. Os concentration and at room temperature. It has been found that the nearest neighbor single Os impurity reduces hyperfine magnetic field on the iron nucleus by 3.97 T, while the second neighbor single Os impurity decreases this field by 1.11 T. More distant impurities slightly increase 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 neighbor Os atom as seen via changes in the isomer shift, i.e. via changes in the spectral shift. The second neighbor 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 neighbor 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.