An amorphous phase in Ln-Fe-Al (Ln=Nd and Pr) systems is formed in wide composition ranges of 0 to 90 at% Fe and 0 to 93 at% Al by melt spinning. Ferromagnetic Ln90-xFexAl10 bulk amorphous alloys with high coercive force (lHc) at room temperature are obtained by copper mold casting. The maximum diameter of the cylindrical amorphous samples is 12 mm for the Nd-30%Fe-Al alloy and 3 mm for the Pr-30%Fe-Al alloys and decreases with deviating Fe content The extremely high Tx/Tm and small ΔTm(=Tm-Tx), which are evaluated by the crystallization (Tx) temperature (Tx) and melting temperature (Tm) , are the reason for the achievement of large glass-forming ability in these systems. The bulk amorphous Ln60Fe30AJ10 alloys are ferromagnetic with the Curie temperature of 515 to 600 K which are higher than those for Nd-Fe and Pr-Fe binary amorphous ribbons. The remanence and lHc are 0.089 to 0.122 T and 277 to 321 kA/m, respectively, and the crystallization to Ln+Al2Ln+δ causes a ferromagnetic- to -paramagnetic transition. Thus, the hard magnetic properties are achieved only in the amorphous state.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering