Magnetic properties of GdxCe1-xCo4M with M=B or Si compounds

The GdxCe1-xCo4B system crystallizes in CeCo4B - type structure, while in case of GdxCe1-xCo4Si compounds, a CaCu5 - type lattice is evidenced. Magnetic measurements were performed in the temperature range 1.5 - 1000 K and fields up to 7 T. The compounds with x>0 are ferrimagnetically ordered. At 1.5 K, the compensation compositions are at x∝0.32 for M=B and 0.45 for M=Si. The mean cobalt moments, as well as the Curie temperatures are strongly dependent on composition. The exchange interactions between and inside magnetic sublattices, as well as the exchange fields acting on the cobalt atoms were computed. Finally, we analyze the experimental data in the model of the induced magnetism. (orig.)