Magnetic properties of melt-spun ribbons of DyFe2-B alloys

Magnetic properties of rapidly solidified ribbons of the alloys (Dy_0.33Fe_0.67)_1-xB_x with x=0, 0.05, 0.1 and 0.15 were investigated as a function of the quench rate during melt-spinning. At low quench rates where the crystalline microstructure has a single phase, room temperature magnetization at 15 kOe (M₁₅) is approximately 60 emu/g and is independent of the B content. The coercive force (H_c), however, increases greatly with the addition of B by a factor of two. This may be due to the increase in magnetocrystalline anisotropy which is generated by a distortion of the highly symmetrical cubic lattice by the introduction of B. At high quench rates where the microstructure mainly consists of an amorphous phase, the values of M₁₅ and H_c are reduced greatly by amorphization and they decrease monotonically with increasing B content