Gd6Co2.2In0.8: an intermetallic compound with complex magnetic behaviour

Electrical, magnetic and thermodynamic measurements have been performed on the rhombic Gd6Co2.2In0.8 intermetallic phase. The experimental data reveal that two magnetic transitions take place. In the first, at 34 K, the magnetic configuration of the sample changes from an antiferromagnetic type to a ferromagnetic type where, however, anti ferro magnetic components, as revealed from magneto-resistivity data, still exist. The second, at 66 K, is the ferro-paramagnetic transition. In the paramagnetic state the low value of the Gd magnetic moment (mu(eff)=6.8 mu(B)), obtained from AC and DC magnetic measurements, can be explained, in the framework of the RKKY theory, by a strong coupling of the conduction electrons with the localized magnetic moments. With respect to the experimental data, a possible hypothesis about the magnetic structure of the phase at 5 K is presented