Peculiarities of magnetization behavior of ferrimagnetic systems (ErCo5-xNix) exhibiting giant intrinsic magnetic hardness

We have investigated the magnetic properties of the ferrimagnetic ErCo5-xNixseries. Particular attention has been given to magnetic hardness and compensation behavior. Unlike the previously investigated ferromagnetic systems (i.e. SmCo5-xNix), which also display giant intrinsic magnetic hardness at low temperatures, the Er analog shows strong asymmetry in measured hysteresis loops. Anomalous magnetic compensation and ill-defined ordering temperatures are also found. This magnetic behavior is attributed, in part, to a locking of moment clusters by the intrinsic coercive force in the compensation region. Data for polycrystalline as well as aligned samples is presented, indicating a new phenomenology for ferrimagnetically coercive materials.