Magnetic and microstructure studies of boron-enriched (Nd/sub 0.95/La/sub 0.05/)/sub 11/Fe/sub 76.5$/ -/sub x/Co/sub x/Ti/sub 2/B/sub 10.5/ (x=0-15) melt-spun ribbons

Abstract

The magnetic properties and microstructures of rare earth lean and boron-rich (Nd/sub 0.95/La/sub 0.05/)/sub 11/ Fe/sub 76.5-x/CoxTi/sub 2/B/sub 10.5/ (x=0-15) melt-spun ribbons have been investigated. Two magnetic phases, namely /spl alpha/-Fe and R/sub 2/Fe/sub 14/B, were found, by thermal magnetic analysis (TMA), in all the ribbons studied. High intrinsic coercivity (iHc) and maximum energy product [(BH)max] values in the range of 14-18.7 kOe and 13.9-18.3 MGOe, respectively, have been achieved in these nanocomposites. Among compositions studied, the Co-substitutions, x/spl les/10, were found to be effective in increasing the Br and (BH)max, while keeping a high value of iHc. It was evidenced from transmission electron microscopy that the homogeneity, fine grain size, and high volume fraction of the R/sub 2/Fe/sub 14/B phase led to an increase in the iHc and maximum energy product of nanocomposites studied. The optimum magnetic properties of Br=9.4 kG, iHc=16.1 kOe and (BH)max=18.3 MGOe have been obtained on (Nd/sub 0.95/La/sub 0.05/)/sub 11/Fe/sub bal./Co/sub 10/Ti/sub 2/B/sub 10.5/ ribbons after an optimum treatment.