ON THE ENERGY-LOSSES OF HOT WORKED ND-FE-B MAGNETS AND FERRITES IN A SMALL ALTERNATING MAGNETIC-FIELD PERPENDICULAR TO A BIAS FIELD

Torsion pendulum magnetometer measurements on ferrites and on neodymiu m-iron-boron permanent magnets are presented. The damping of the oscil lation of the pendulum leads to information on the magnetic energy los ses of the magnets in a small alternating magnetic field applied perpe ndicular to a bias field. The origin of the energy absorption is expla ined by the magnetization reversal of single-domain particles. It is s hown experimentally that the energy absorption mechanism requires the ferromagnetic order of the sample, and that the magnetic held strength of maximal energy absorption coincides with the effective anisotropy field strength.