Structure and Magnetic Properties of Ni_0.77Fe_0.16Cu_0.05Cr_0.02 Doped with Co

Ni_0.77Fe_0.16Cu_0.05Cr_0.02 (Mumetal) is a soft magnetic material with high magnetic permeability and low coercivity. This alloy is very suitable for producing magnetic shields. The present experimental study focuses on the synthesis and evaluation of the magnetic properties of Co-doped Mumetal, i.e., Ni_0.77−xCo_xFe_0.16Cu_0.05Cr_0.02 components at x = 0.02, 0.05 and 0.10. These components were synthesized by mechanical alloying process using a high-energy planetary ball mill. Structure, microstructure and magnetic properties during the milling process has been studied using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometer (VSM) and inductance/capacitance/resistance meter techniques. The results indicate that saturation magnetization and magnetic permeability of Mumetal improve by addition of Cobalt in such a way that sample with x = 0.10 shows a maximum permeability and minimum magnetic loss (at frequency < 50 kHz). Therefore, this alloy is the most appropriate for producing magnetic shields.