MAGNETIC-PROPERTIES OF MICROCRYSTALLINE SMCOX ALLOYS BY MELT-SPINNING

High-coercivity SmCox alloys were prepared by melt spinning. X-ray dif fraction data indicate that the alloys exhibit a single phase SmCo5 an d Sm2Co17 structure at x = 5.0 and x = 8.5, respectively. A two-phase structure appears at 5.0 < x < 8.5. The coercivity of the studied allo ys increases as the wheel speed is increased up to a maximum value of 40 m/s. The grain sizes of the as-spun alloys were measured to be 0.1- 1.0 mu m. The high coercivity of the microcomposite alloys can be expl ained from the unpinning of domain walls at nucleation sites.