Magnetic properties of the YCo3–H system

The YCO 3 -H system is an interesting system, which shows a dramatic influence of hydrogen absorption on its magnetic properties. The β-hydride phase has been divided into β 1 and β 2 phases originally due to their different magnetic properties. Our measurement of the absorption isotherm at room temperature, however, shows clearly that the β phase is actually separated into two phases. Thus a new hydride phase has been identified. Magnetisation measurements have also been made using a VSM. The results show that the β 1 phase is most likely to be paramagnetic. We also observe that the β 2 phase seems to have two Curie temperatures. Because there are three types of Co atoms in the YCo 3 structure, we would infer that the magnetic ordering of the different Co atoms takes place at different temperatures in this phase.