The effect of crystallization on microstructure and magnetic properties of Fe61Co7Zr9.5Mo5W2B15.5 bulk metallic glass

The effect of crystallization on microstructure and magnetic properties of Fe61Co7Zr9.5Mo5W2B15.5 bulk metallic glass (BMG) was investigated using X-ray diffraction (XRD), differential thermal analyzer (DTA ), transmission electron microscopy (TEM) and vibrating samples magnetometer (VSM). Without annealing, the as-cast alloy exhibits paramagnetic properties. However, the magnetic properties and the microstructure change significantly when isothermal annealing is applied to the alloy. In particular, at different annealing temperatures, the coercivity (Hc) of the alloy changes from a minimum value of 7.3 Oe to a maximum value of 196.9 Oe. The dependence of coercivity and saturation magnetization on microstructure is discussed in terms of magnetic domain wall pinning and magnetic exchange interaction.