The effect of milling time and composition on microstructural and magnetic properties of nanostructured Fe–Co alloys

Nanostructured FexCo1−x (x = 1, 0.9, 0.65, 0.5, and 0.25) powders were produced by high energy milling with different milling times and examined by X-ray diffraction and scanning electron microscope. Some magnetic properties at room temperature were measured by a vibration sample magnetometer. According to the present experiment, a body-centred cubic nanostructured Fe–Co alloy resulted with an average crystallite size of about 12–15 nm by milling for 8 h. With increasing the milling time, the lattice parameter increased for Fe and Fe–10%Co powders; while decreased for higher concentrations of Co. The maximum saturation magnetization (MS) occurs at a concentration of 35 at.% Co after milling for 45 h. The coercivity increased until 3 h milling, followed by a noticeable reduction by milling for 8 h and then remained constant. In addition, the coercivity gradually increased by increasing the Co content.