Magnetic properties of Nd8Fe77Co5B6CuNb3 melt-spun ribbons

Nd8Fe77Co5B6CuNb3 amorphous ribbons were obtained by the melt spinning meth od using a large range of the wheel circumferential speed (18-40 m/s). For 10 min time of heat treatment at 700 degrees C the following values of the magnetic characteristics were achieved: H-c = 3.95 kOe, B-r = 11.25 kG, and (BH)(max) = 15 MGOe. The 13% increase of the remanent ratio M-r/M-1.5T by applying a magnetic field during annealing suggests an improvement of the e xchange coupling effect. The Curie temperature of both hard and soft magnet ic component phases increases with about 50 degrees C due to the Co content but it is not affected by the magnetic field annealing. (C) 1998 American Institute of Physics.