The hard magnetic properties of nanocomposite Nd-3.6Pr5.4Fe83Co3B5 ribbonsprepared by melt spinning

Nanocomposite Nd3.6Pr5.4Fe83Co3B5 ribbons were prepared by direct melt spin ning at different wheel speeds. The hysteresis loop of the ribbons prepared at wheel speed V = 20 m/s shows a single hard magnetic behavior with high coercivity. The values of remanence M-r = 11.3 kG s, intrinsic coercivity H -i(c) = 6.0 kOe and energy product (BH)(max) = 17.2 MG Oe are obtained at r oom temperature. Transmission electron microscopy and magnetic force micros copy have been employed to image the microstructure and magnetic domains in the ribbons. Due to the unnegligible inter-grain exchange coupling, intera ction domains are observed. The shape of the demagnetization curve in the s econd quadrant at different temperature gives more information about inter- grain exchange coupling. The coercivity mechanism is discussed. (C) 2001 El sevier Science B.V. All rights reserved.