Effect of Co and Dy substitutions on the structure and magnetic properties of Nd–Fe–C alloys prepared by a re-milling process

The effect of Co and Dy substitutions on the structure and magnetic properties of Nd–Fe–C alloys prepared by a re-milling process has been investigated. The main magnetic phase Nd2(Fe,Co)14C coexists with a small amount of Nd2C3 and Nd-rich phase in Nd16Fe76−xCoxC8 (0 ≤ x ≤ 20) alloys. The Co substitution for Fe enhances the Curie temperature Tc and magnetic properties of the alloys. The remanence 4πMr, saturation magnetization 4πMs and maximum energy product (BH)max of the Nd16Fe76−xCoxC8 (0 ≤ x ≤ 20) alloys increase up to a maximum for x = 10. For Nd16−yDyyFe66Co10C8 (0 ≤ y ≤ 16) alloys prepared by re-milling and subsequent annealing, the introduction of Dy enhances the intrinsic coercivity due to the increase of anisotropy of the Nd2Fe14C-type phase.