Magnetic studies of melt spun NdFeAl-C alloys

摘要

Alloys with compositions Nd60-xCxFe30Al10 (x=0, 1, 5 and 10) were processed by melt spinning at a tangential speed of 5 m/s. The as-cast ribbons were characterized by X-ray diffraction, Mossbauer Effect spectroscopy and their room temperature hysteresis loops. The substitution of Nd by C is found to affect the phase selection, from mainly DHCP-Nd for x = 0 to DHCP-Nd/FCC-Nd for the other ones. Mossbauer spectra of all the as-cast samples indicate that Fe is present in crystalline magnetic phases as well as in a paramagnetic one. The major crystalline phase was identified as a mu-type (or A1) metastable phase, which is reported to have a large anisotropy field and a relatively high saturation polarization. Interstitial C stabilizes the mu-type phase and improves its average hyperfine field. The magnetic measurements display an increase of coercivity and remanence with the C concentration. (C) 2004 Elsevier B.V. All rights reserved.