Systematics in the 4f-3d exchange interaction in intermetallic compounds

The 4f-3d interaction in a large variety of intermetallic compounds based on a heavy rare-earth (R) and a transition metal (T=Fe, Co, Ni) has been derived from the magnetisation processes associated with the breaking up of the ferrimagnetic ground-state configuration in these compounds. The magnetisation measurements have been carried out at 4.2 K in fields up to 38 T in the High Field Facility at the University of Amsterdam on small single-crystalline particles that are free to rotate in the external field. (orig.)