Comparison on the magnetic and structural properties of Sm(Co0.67-xFe0.25Cu0.06Zr0.02Cx)(8.0), where x = 0-0.15, melt spun ribbons and cast alloys

The effects of C additions on the phase transformation and magnetic propert ies of Sm(Co0.67-xFe0.25Cu0.06Zr0.02Cx)(8.0), where x ranged from 0 to 0.15 , melt spun ribbons and cast alloys have been studied by x-ray diffraction (XRD), differential thermal analysis (DTA), and vibrating sample magnetomet er. In addition to the Th2Zn17 structure, two additional compounds, namely, the ZrC and SmCoC2, were detected by XRD after a thermal treatment over 70 0-1160 degrees C. The as-spun ribbons were highly crystalline at x = 0 and became mostly amorphous at x = 0.10. An intrinsic coercivity, H-ci, of 3.0 kOe was obtained for the as-spun ribbons with x = 0.05. After an optimum he at treatment, the H-ci of the ribbons with x = 0.01 was increased to 8 kOe. Cast alloys of identical chemical compositions were also solution treated and precipitation hardened. At x = 0 for the cast alloy, a B-r of 10.8 kG, H-ci of 24 kOe, H-c of 9.8 kOe, and (BH)(max) of 27 MGOe, were obtained aft er an optimum heat treatment. (C) 1999 American Institute of Physics.