PERMANENT MAGNET AND METHOD FOR PRODUCING PERMANENT MAGNET

摘要

Disclosed is a method for producing a permanent magnet with high productivity at low cost. In this method, Dy and/or Tb is adhered to the surface of a certain-shaped iron-boron-rare earth sintered magnet and dispersed into the crystal grain boundary phase of the sintered magnet. Specifically, an iron-boron-rare earth sintered magnet is placed in a process chamber and heated to a certain temperature, while evaporating an evaporation material V which is placed in the same or a different process chamber and composed of a fluoride containing at least one of Dy and Tb. The vaporized evaporation material is adhered to the surface of the sintered magnet, and metal atoms of Dy and/or Tb in the adhering evaporation material are dispersed into the crystal grain boundary phase of the sintered magnet before a thin film of the evaporation material is formed on the surface of the sintered magnet.