Effect of Fe substitution by Ti or Nb/V/Zr on phase stability and magnetic properties of Pr2Fe23(B, C)3 ribbons

The effect of refractory elements on the phase evolution and magnetic properties of melt-spun Pr2(Fe0.975M0.025)23B3 (M=Ti, Nb, V and Zr) ribbons has been investigated. Based on thermal magnetic analysis (TMA), a slight substitution of the selected refractory elements (Ti, Nb, V, and Zr) for Fe in Pr2(Fe0.975M0.025)23B3 can suppress the formation of metastable Pr2Fe23B3 and Fe3B phases and result in the presence of large amount of Pr2Fe14B and α-Fe phases of fine grain size (15–40nm). The magnetic properties of the above ribbons are all improved remarkably, whereas M=Ti is the best among them. By increasing the concentration of Ti, the optimal magnetic properties of Br=9.9kG, iHc=6.8kOe, and (BH)max=16.1MGOe have been obtained in Pr2(Fe0.970Ti0.030)23B3. Furthermore, incorporating C with refractory elements Nb or Zr is effective in improving the coercivity of Pr2(Fe,M)23(B,C)3 (M=Nb and Zr) ribbons.