Effect of heat treatments on the magnetic properties of SmCo5single crystals

The heat treatment effects on the magnetic properties, especially on the coercivity for SmCo5single crystals, are reported. There is a peak at 1080°C in the annealing temperature dependence of coercivity for SmCo5single crystals. The variations of the coercivity with annealing temperature are similar between SmCo5single crystals and Sm-Co sintered magnets. It is noted that the coercivity of SmCo5single crystals remarkably decreases by occurrence of scratches and oxides on the surface of the specimens. It seems that the decrease of coercivity in this crystal is due to nucleation of domain walls caused by crystalline defects.