Mechanism Of Magnetic Field Annealing On Increasing Both Coercivity And Magnetization Of Sm(Co0.9cu0.1)(5) Ribbons

Sm(Co0.9Cu0.1)(5) ribbons melt-spun at 40 m/s are composed of cellular structure with 13.8 % Sm-2(Co, Cu)(7) cell walls encircling the Sm(Co, Cu)(5) intracellular grains, which have the magnetic properties of Hc = 9.5 kOe, Mr = 39.4 emu/g, and M-s = 44.1 emu/g. After vacuum annealing at 450 degrees C, the ribbons keep the original cellular structure and phase composition, Hc increases by 18.9 %, and the magnetization changes little. In contrast, magnetic field annealing (MFA) increases H-c, M-r, and M-s by 64.2 %, 11.4 %, and 15.0 %, respectively. The mechanism of MFA on increasing both coercivity and magnetization of the ribbons can be attributed to the enhanced field-induced anisotropy, the refined cellular structure, the uniform distribution of the lower Cu content at 3g and 2c sites of Sm(Co, Cu)(5) phase, and the higher Cu content in the cell walls. Besides, the microstructure evolution models of the different types of ribbons are proposed.