Hyperfine interactions in Gdsub(x)Ysub(1-x)Fesub(2) compounds

Results of Moessbauer measurements on Gdsub(x)Ysub(1-x)Fesub(2) compounds in a large temperature range are presented. The direction of the easy axis of magnetization have been determined as function of temperature and composition. The spin reorientation diagram is discussed considering the competing influences of the anisotropy of the iron sublattice and that of the exchange interactions. The composition dependence of the hyperfine parameters is analyzed. The thermal variation of the hyperfine fields suggests that the largest part of 3d electrons of iron are in the narrow band and can be considered localized