METHOD OF PRODUCING R-T-B SINTERED MAGNET

This invention includes : an application step for applying an adhesive to an application region of the surface of an R-T-B sintered magnet; an adhesion step for causing a granularity adjustment powder formed from a powder of a compound or an alloy of a heavy rare earth element RH, which is Dy and/or Tb, to adhere to the application region of the surface of the R-T-B sintered magnet; and a diffusion step for performing a heat treatment at a temperature equal to or lower than the sintering temperature of the R-T-B sintered magnet and causing the heavy rare earth element RH contained in the granularity adjustment powder to be diffused from the surface of the R-T-B sintered magnet to the interior. The granularity of the granularity adjustment powder is set so that the amount of the heavy rare earth element RH contained in the granularity adjustment powder is in a range of 0.6-1.5% by mass in relation to the R-T-B sintered magnet when the powder particles constituting the granularity adjustment powder are disposed across the entire surface of the R-T-B sintered magnet to form a single particle layer.