Dependence of magnetic properties of HDDR Nd-Fe-B bonded magnet on intergranular phase

Using proposed different anisotropy expressions K₁'(r) and K₁'(r) at the grain boundary, we investigate the effect of intergranular phase (IP) on the average anisotropy of grain boundary and the coer-civity Hc of HDDR (hydrogenation, disproportionation, desorption and recombination) Nd-Fe-B bonded magnet. The results indicate that when the IP’s thickness d is zero, and Hc based on K₁'(r) are equal to the corresponding ones based on K₁'(r). While d takes nonzero values, and Hc based on K₁'(r) falls and rises more rapidly, respectively, with increasing d. When d is 1 nm and the structure defect thickness r0 is close to the thickness of domain wall (~4 nm), the calculated coercivity is con-sistent well with the avaiable experimental data.