Structure and magnetic properties of Pr2Fe14(C,B)-type ribbons with high coercivity

The effect of the substitution of B for C on the structure and magnetic properties of the Pr15Fe77C8−xBx (x=0–8) ribbons has been investigated. Microstructure analysis shows that the grain size and size distribution of the ribbons with x⩾2 do not change with B substitution. It is found that B substitution significantly improves the hard magnetic properties of the samples. The coercivity, remanence, and energy product increase from 0.0002 and 0.19 T and 0.001 MGOe for x=0 to 2.19 and 0.76 T and 14.3 MGOe for x=8, respectively. Without heat treatment, Pr2Fe14C-type ribbons with high coercivity of greater than 2 T have been prepared by melt spinning. The introduction of B changes the phase components, and leads to a substantial difference in coercivity mechanisms of the B-poor ribbons (x=2) and B-rich (x=8) ribbons.