SINTERED MAGNET AND PRODUCTION PROCESS THEREFOR

摘要

The purpose of the present invention is to improve the magnetic characteristics of a sintered magnet without adding a supplementary heavy rare earth element. A sintered magnet composed of an NdFeB main phase and a grain boundary phase, wherein: the grain boundary phase contains an oxyfluoride; the concentration of fluorine in the oxyfluoride decreases depthwise from the surface of the sintered magnet toward the center thereof; and the heavy rare earth element concentration of the oxyfluoride at the surface of the sintered magnet is nearly equal to that at the center thereof.