Effects of Mo additive on structure and magnetic properties of Co82Zr18 alloy

The structure and magnetic properties of Zr18Co82−xMox (1 ≤ x ≤ 5) melt-spun ribbons are studied systematically by X-ray diffraction analysis and magnetic measurements. We find a single Co5Zr phase in Zr18Co77Mo5 melt-spun ribbons, which has a Curie temperature of 450 °C. The coercivity of Co–Zr–Mo melt-spun ribbons increases monotonously from 1.9 to 4.1 kOe with increasing Mo content. Annealing of the Zr18Co77Mo5 melt-spun ribbons results in a decrease of the coercivity. The hard magnetic phase is confirmed to Co5Zr phase in Co–Zr–Mo melt-spun ribbons. The coercivity mechanism of Co–Zr–Mo melt-spun ribbons is found to be reverse domain nucleation type.