The magnetization behavior of melt-spun FeDy-B alloys

We report the salient features of the magnetization behavior of melt-spun r ibbons of (Dy0.33Fe0.67)(1-x)B-x with x = 0, 0.05, 0.1 and 0.15 alloys. The temperature dependence of magnetization and low-temperature hysteresis loo ps were measured using a vibrating sample magnetometor during heating from 5 to 900 K, with an applied field of 50 kOe. Our results show that the addi tion of B seems to decrease the magnetic order and hence to decrease the ex change stiffness and the Curie temperature. Very large values of the coerci ve force at a low temperature of 5 K, ranging from 19 800 to 22900 Oe, was observed. The rapid increase of the coercive force at low temperatures is e xplained by the topological disorder due to the presence of rare earth spin s distributed randomly. (C) 2001 Elsevier Science B.V. All rights reserved.