Effects of Al substitution on intersublattice-exchange interaction in GdCo_5-xAl_x

The strength of the intersublattice Gd-Co exchange-coupling parameter, A_GdCo, and the magnetic moment of the Co sublattice, M_Co, are reported for the GdCo_5-xAl_x (x = 0, 0.5, 1.0, 1.5 and 1.8) compounds. As the Al content increases, a tendency to decrease is found for both A_GdCo and M_Co. In comparison with a previous study of Gd-Co-B series, a systematic influence of 3d-p hybridization on the 4f-3d exchange coupling is evident. These results are discussed in terms of the magnetic valence model.