SINTERED MAGNET AND PROCESS FOR PRODUCTION THEREOF

摘要

The purpose of the present invention is to improve the magnetic characteristics of a sintered magnet without any additional 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 is higher than that of oxygen therein; the concentration of fluorine in the oxyfluoride decreases depthwise from the surface of the sintered magnet toward the center thereof; and the saturation magnetic flux density of the sintered magnet decreases depthwise from the surface of the sintered magnet toward the center thereof.