Coercivity of rapidly quenched Nd₆₀Fe₃₀Al₁₀ alloys

High coercivities were obtained in partly amorphous Nd₆₀Fe₃₀Al₁₀ ribbons that had been melt spun at 5 m s^-1 and in a water-quenched rod, whereas low coercivities were obtained in fully amorphous ribbons that had been melt spun at high wheel speeds (>20 m s^-1). High coercivities were measured for the water-quenched and the chill-cast rods. This result indicates that the coercivity of the Nd-Fe-Al alloy is strongly dependent on the quenching rate. The magnetic properties of the water-quenched rod were studied as functions of temperature. The coercivity increased from 318 kA m^-1 at room temperature to 2085 kA m^-1 at liquid nitrogen temperature. The ribbon that had been melt spun at 5 m s^-1 possessed a coercivity of 3266 kA m^-1 (4.1 Tesla) at 78 K. Such high coercivities were attributed to a large local magnetic anisotropy which is probably produced by Nd atoms.