The &agr;-Fe/R2Fe14B-type exchange-coupled NdFeB nanocomposites with a coercivity(iHc) of more than 11 kOe and energy product,(BH)max,of more than 16 MGOe have been successfully obtained on melt spun(Nd0.95La0.05)7.5+xFebalCr2B10alloy powders, wherexranged from 3 to 3.5. It was found that a slight substitution of Cr for Fe suppresses the formation of theR2Fe23B3andFe3Bphases during crystallization and results in the formation of an &agr;-Fe/R2Fe14Bmixture. Increasing the total rare earth content was found to enhance the remanence, and theiHcof(Nd0.95La0.05)7.5+xFe80.5−xCr2B10ribbons was also increased drastically with increasing values ofx. ABrof 9.2–9.7 kG,iHcof 11.1–13.2 kOe, and(BH)maxof 16.5–18.0 MGOe have been obtained on(Nd0.95La0.05)7.5+xFe80.5−xCr2B10(x=3–3.5). ©1998 American Institute of Physics.