A comparative study of the microstructure and magnetic properties of melt-spun RE2Fe14B/α-Fe and RE2Fe14B/Fe3B nanocomposites

The microstructure and magnetic properties of RE₂Fe₁₄B/α-Fe and RE₂Fe₁₄B/Fe₃B nanocomposites are compared using X-ray diffractometry, thermogravimetric analysis, transmission electron microscopy, and magnetometry. The compositions of Nd₉Fe₈₆B₅, Pr₉Fe₈₆B₅, Nd₉Fe₇₉B₁₂ and Pr₉Fe₇₉B₁₂ are prepared using an arc melting and melt spinning route. E₉Fe₈₆B₅ samples are found to exhibit finer and more uniform microstructures, higher B_r, (BH)_max and more square demagnetization curves than their RE₉Fe₇₉B₁₂ equivalents. The higher performance of RE₂Fe₁₄B/α-Fe nanocomposites can be attributed to the more favorable intrinsic magnetic properties of α-Fe and a much finer structure. The results indicate that RE₂Fe₁₄B/α-Fe is a more desirable system for future developments of high performance nanocomposite magnets.