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.Tix,B11-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 (B-r), intrinsic coercivity (H-i(c)) 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 B-r, H-i(c), and (BH)(max) a monotonically. lt arises from the increase of volume fraction of Pr2Fe17Cz, and alpha-Fe phases, and the rapid decrease of 2:14:1 phase. The attractive properties of B-r = 9.7 kG, H-i(c), = 7.8 kOe, (BH)(max) = 13.1 MGOe and alpha = -0.130 %/degrees C, beta = -0.615 %/degrees C are obtained in Pr9Febal.B10.5C0.5 nanocomposites, on the other hand, the optimal properties of B-r = 9.5 kG, H-i(c) = 10.8 kOe, (BH)(max) = 17.8 MGOe and alpha = -0.135 %/degrees C, beta = -0.576 %/degrees C are achieved in Pr9Febal.Ti2.5B11 nanocomposites. (c) 2006 Published by Elsevier B.V..