On the relationship between magnetic moment and nuclear magnetic hyperfine field of 57Fe

The relationship between the internal magnetic hyperfine field, Bhf, and the measured magnetic moment of Fe, μFe, has long been a challenge in Mossbauer spectroscopy, nuclear physics and materials science. In many publications, it has been reported that Bhf and μFe are proportional. In contrast, in the present work, it will be shown that the macroscopic measured magnetic moment by methods such as SQUID is the sum of the magnetic moment of delocalized electrons with 3d-character, μ3d, and the moment of electrons with sp-character, μsp. The sp. moment is, however, less significant for the arising of magnetic hyperfine field. Therefore, the direct relation of measured magnetic moment to magnetic hyperfine field of Fe leads to inaccurate interpretations. Instead, it can be shown that Bhf is associated with μ3d. The constant of proportionality, frequently used in Mossbauer spectroscopy, is typically determined from the relationship between measured values of the magnetic moment and the hyperfine fields. Based on the present findings, the constant of proportionality is the results of the relationship between Bhf and the delocalized magnetic moment, μ3d, which is different from the measured magnetic moment. The use of the correct constant of proportionality relating Bhf to the magnetic moment allows the separation of μ3d and μsp. In the present work, this relationship has been studied for crystalline Fe, amorphous Fe90Sc10 and (Fe100-xCoX)90Sc10 alloys, prepared as homogeneous structures or in the form of heterogeneous nanoglass.