ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The effect of phase transformations on the magnetic properties of rare earth lean (Nd0.95La0.05)9.5Fe82.5−xCr2B6+x (x=0 to 4.5) and (Nd0.95La0.05)7.5+yFe80.5−yCr2B10 (y=0 to 4) melt spun ribbons has been investigated. The phase mixture, after optimum thermal processing, was found to be strongly dependent upon the rare earth and boron contents. Two magnetic phases, namely α-Fe and R2Fe14B, were found in (Nd0.95La0.05)9.5Fe82.5−xCr2B6+x alloy ribbons with x ranging from 0 to 4.5. For a fixed rare earth content, increases in the boron concentration resulted in a higher volume fraction of the R2Fe14B phase, which led to an increase in the intrinsic coercive force from 7.1 kOe for x=0 to 12.6 kOe for x=4.2. A Br=9.6 kG, iHc=9.5 kOe, and (BH)max=15.5 MGOe have been obtained in the alloy ribbons with x=4.5. On the other hand, the increase in the total rare earth content, or y, was found to suppress the formation of the metastable Fe3B and/or R2Fe23B3 phases and to yield an α-Fe/R2Fe14B mixture for y〉1. This increase in total rare earth content not only increases the volume fraction of both the R2Fe14B and α-Fe phases but also decreases the average grain size of these phases as evidenced by transmission electron microscopy analysis. This decrease in the average grain size may subsequently enhance the intrinsic coercivity and the remanence of the ribbons. A Br of 9.5 kG, a iHc of 13.2 kOe, and a (BH)max of 18 MGOe were achieved in (Nd0.95La0.05)11Fe77Cr2B10. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.367572
