Structural and magnetic properties of Nd60Fe30-xCoxAl10 melt-spun ribbons

The effects of Co addition on the structure and magnetic properties of melt-spun Nd60Fe30-xCoxAl10 (x=0, 2, 5, 10, 20, and 30) ribbons have been investigated. Except an amorphous matrix, nanocrystalline Nd was found in the Fe-containing alloys. Its relative amount decreases with increasing Co addition, and a fully amorphous structure was observed for x=30, indicating that glass-forming ability increases with Co addition. The room-temperature coercivity and magnetization are found to decrease sharply with increasing Co content. Thermomagnetic measurements show two magnetic transitions occurring at about 50 K and 480 K, respectively. Combining the isothermal differential scanning calorimetry measurement, it demonstrated that the amorphous phase in the Fe-contained alloys further separates into Nd-rich regions and Fe-rich regions. The relative amount of each phase is estimated by the magnetization of each phase. (C) 2003 American Institute of Physics.