RFeB system magnet production method, RFeB system magnet, and coating material for grain boundary diffusion treatment

An RFeB system magnet having a main phase made of R2Fe14B containing a rare-earth R, iron Fe and boron B, satisfying a following relationship:

• 0<x1≤0.5, 0≤x2, and
• HcJ≥20.8×x1+2×x2+14.7 (1)
• where x1 and x2 respectively represent weight percentages of Tb and Dy, and HcJ represents coercivity in kOe at room temperature, wherein:
• the RFeB system magnet has a thickness of 5.5 mm or less;
• Tb content at a position in the RFeB system magnet is higher as the position is closer to a surface of the RFeB system magnet;
• and
• a difference between the maximum and the minimum in a coercivity at positions in the RFeB system magnet is 1 kOe or less.

An RFeB system magnet having a main phase made of R2Fe14B containing a rare-earth R, iron Fe and boron B, satisfying a following relationship:

• when 0<x2≤0.7
• HcJ≥8.6×x2+14 (2)
• and when 0.7<x2
• HcJ≥2×x2+18.6 (3)
• where x2 represents a weight percentage of Dy, and HcJ represents coercivity in kOe at room temperature, wherein:
• the RFeB system magnet has a thickness of 5.5 mm or less;
• Tb content at a position in the RFeB system magnet is higher as the position is closer to a surface of the RFeB system magnet;
• and a difference between the maximum and the minimum in a coercivity at positions in the RFeB system magnet is 1 kOe or less.