Magnetic properties of amorphous Nd–Fe–Co–Al alloys

Nd60FexCo30−xAl10 (0≤x≤30) alloys were prepared by copper mold casting. The magnetic properties were studied by VSM and SQUID magnetometers. These measurements show the presence of two different magnetic phases with ordering temperatures of 50 K and 496 K for the Fe-containing alloys. A step in the M–H hysteresis loops at temperatures below 50 K supports the presence of the two different magnetic phases. The temperature dependence of the coercivity exhibits a peak at about 50 K above which it follows a law that describes hard magnetic behaviour based on pinning site inhomogeneities interacting with domain walls.