R-t-b based permanent magnet

An R-T-B based permanent magnet including a rare-earth element R, a transition metal element T, and B,

• wherein the R-T-B based permanent magnet includes at least Nd as the R,
• the R-T-B based permanent magnet includes at least Fe as the T,
• the R-T-B based permanent magnet contains a plurality of main phase grains,
• the plurality of main phase grains includes at least the R, the T, and B,
• a plurality of voids are formed in a cross-section of the R-T-B based permanent magnet,
• the cross-section is approximately parallel to an easy magnetization axis direction of the R-T-B based permanent magnet,
• an area ratio of the plurality of voids in the cross-section is from 1% to 5%,
• a direction orthogonal to the easy magnetization axis direction in the cross-section is expressed as AB direction,
• a direction in which each of the plurality of voids extends in the cross-section is expressed as VD,
• an angle between the AB direction and the VD is expressed as θ,
• a horizontal axis of a frequency distribution of the plurality of voids in the cross-section represents the θ,
• a range of the horizontal axis of the frequency distribution is from 0° to 180°, and
• the frequency distribution is maximum in a range of θ of from 60° to 120°.