Symmetric hysteresis curves of rare earth-cobalt magnets measured by high magnetic fields

SmCo5magnets show generally asymmetrical hysteresis curves in the region of ordinary magnetic field strength. However, if these magnets are magnetized by a field of over 14 T, hysteresis loop becomes symmetric, except for the experimental errors caused by the thermal fluctuation after effect. The influence of the after effect on the magnetization curve and the coercive forceIHCare discussed.