Internal Magnetization Density Distribution of Iron and Nickel by the Maximum Entropy Method

We have reanalysed the polarized neutron data for the magnetic form factors of Fe (Shull and Yamada, 1962) and Ni (Mook, 1966, Maniawski et al. , 1981) using the model-free Maximum Entropy technique. The magnetic anisotropy of e g and t 2g types, respectively, is clearly visible. An apparently new feature observed is a depletion of the magnetization density at nuclei positions. One can prove that its observation was possible because of an enhanced spatial resolution of the MaxEnt method. From a model-free MaxEnt point of view, effect of a presence of the negative magnetization is of the order of the sensitivity of MaxEnt. The data can be fitted almost equally well by a strictly positive or a positive/negative magnetization distribution, which agrees with conclusions of Dobrzynski (1976) and Kaprzyk et al. (1981). If presence of the negative magnetization is assumed, the corresponding form factors give contribution to the innermost reflections and vary in an oscillatory manner.