The influence of Gallium doping on the magnetic performance and microstructure of Nd-Fe-B sintered magnets

•The intrinsic coercivity increases from 12.4 kOe to 19.4 kOe and the remanence slightly decreases from 14.03 kGs to 13.70 kGs when Ga content increases from 0.0 wt% to 0.5 wt%.•The addition of Ga can promote the diffusion of Nd and Cu from triple junction phase (TJP) into grain boundary phase and accumulate Fe at TJP.•Both the enhancement of coercivity and the increased Curie temperature lead to the improvement of the thermal stability.