Production method for R-T-B sintered magnet

A method for producing a sintered R-T-B based magnet, comprising:

• a step of providing a sintered R-T-B based magnet, where R is one or more rare-earth elements, T is one or more transition metal elements, and B is boron or is boron and carbon;
• and
• a step of performing a heat treatment at a sintering temperature of the sintered R-T-B based magnet or lower, while a powder of an Nd—Cu alloy consisting of Nd and Cu which is produced through atomization and a powder of an RH compound (where RH is Dy and/or Tb;
• and the RH compound is one or more selected from among an RH oxide, an RH fluoride, and an RH oxyfluoride) are present on a surface of the sintered R-T-B based magnet, wherein,
• the Nd—Cu alloy contains Nd in an amount of 50 at % or more, and a melting point of the Nd—Cu alloy is equal to or less than a temperature of the heat treatment;
• a particle size of the RH compound powder is smaller than a particle size of the Nd—Cu alloy powder;
• and
• the heat treatment is performed while the Nd—Cu alloy powder and the RH compound powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of Nd—Cu alloy:
• RH compound=9.6:0.4 to 5:5 so that the RH compound powder is reduced by the Nd—Cu alloy powder to diffuse an RH element that is contained in the RH compound powder into the sintered R-T-B based magnet.