Magnetic phase diagrams of Ce2Fe17−xMnx-H system: A magnetization study

The field-induced magnetic phase transitions of the helical phase of Ce2Fe17−xMnx alloys (x=1.3 and 1.7) and their hydrides of Ce2Fe17−xMnxHy (y=1) were investigated by isofield magnetization curves in external magnetic fields up to H=10  kOe. The temperature dependence of the critical fields, HC inducing phase transition between ferromagnetic (F) and helical antiferromagnetic (HAFM) state are determined. On the basis of the experimental results, the H -T phase diagrams are established. The multiple magnetic phase transitions observed in the low magnetic field are discussed in terms of competing exchange contributions within the iron magnetic sublattices. Hydrogenation leads to a considerable enhancement of ferromagnetic-like exchange interactions, which causes the increase of the Curie temperature and drastically reduces the critical field HC of a metamagnetic transition.