Ferrimagnetism in GdCo12-xFexB6
Résumé
The effects of iron substitution on the structural and magnetic properties of the GdCo12-xFexB6 (0 <= x <= 3) series of compounds have been studied. All of the compounds form in the rhombohedral SrNi12B6-type structure and exhibit ferrimagnetic behaviour below room temperature: T-C decreases from 158 K for x = 0 to 93 K for x = 3. Gd-155 Mossbauer spectroscopy indicates that the easy magnetization axis changes from axial to basal-plane upon substitution of Fe for Co. This observation has been confirmed using neutron powder diffraction. The axial to basal-plane transition is remarkably sensitive to the Fe content and comparison with earlier Fe-57-doping studies suggests that the boundary lies below x = 0.1.