Investigation of magnetic properties, phase evolution, and microstructure of melt spun PrFeTiBC nanocomposites

Microstructure, phase evolution, and magnetic properties of Pr-lean and B-excess Pr9Febal.TixB11−yCy (x = 0 and 2.5; y = 0–11) ribbons have been investigated. For Pr9Febal.B11−yCy (Ti free) series ribbons, the effect of slight C addition not only forms the Pr2Fe14(B,C) phase but also refines the grain size, yielding an increase in the remanent magnetization (Br), intrinsic coercivity (iHc) and energy product ((BH)max). For Pr9Febal.Ti2.5B11−yCy series ribbons, substitution of Ti suppresses the formation of metastable Pr2Fe23B3 phase and ensures the existence of large amount magnetically hard Pr2Fe14B phase. However, the increase of C substitution in the Pr9Febal.Ti2.5B11−yCy (y  = 0–11) ribbons degrades Br, iHc, and (BH)max monotonically. It arises from the increase of volume fraction of Pr2Fe17Cz and α-Fe phases, and the rapid decrease of 2:14:1 phase. The attractive properties of Br = 9.7 kG, iHc = 7.8 kOe, (BH)max = 13.1 MGOe and α = −0.130 %/°C, β = −0.615 %/°C are obtained in Pr9Febal.B10.5C0.5 nanocomposites, on the other hand, the optimal properties of Br = 9.5 kG, iHc = 10.8 kOe, (BH)max = 17.8 MGOe and α = −0.135 %/°C, β = −0.576 %/°C are achieved in Pr9Febal.Ti2.5B11 nanocomposites.