Magnetic Viscosity of Nd60Fe20Co10Al10 Bulk Amorphous Alloy during Crystallization Process

The Nd60Fe20Co10Al10 bulk amorphous alloy was prepared by suction casting into the copper mould. The microstructure and magnetic property of the alloy during the crystallization process were studied. The magnetic viscosity of this alloy during crystallization process was investigated by a waiting time method. Results indicate that magnetic properties of the Nd60Fe20Co10Al10 bulk amorphous alloy annealed below 783 K have a slight change. However, after annealing above 783 K, values of the remanence (M-r), saturation magnetization (M-s) and intrinsic coercivity (H-i(c)) decrease significantly. Furthermore, the alloy shows paramagnetic behavior after annealing at 803 K. When samples are annealed at 703 K and 753 K, the activation volume (v(a)) and activation diameter (D-a) change a little, while the fluctuation field (H-f) exhibits a maximum at 703 K, which is attributed to a metastable phase. The relationship between parameters of magnetic viscosity and magnetic property of the Nd60Fe20Co10Al10 alloy was discussed.