Magnetic properties and microwave absorption characteristics of CoFe alloy microparticles studied by the FORC method

Despite extensive research on CoFe alloy microstructures for their adjustable magnetic properties in applications such as microwave devices, biomedicine, and environmental cleanup, their exact magnetic behavior remains inadequately understood. A chemical reduction process is employed to manufacture CoFe alloy microparticles (MPs) with varying compositions (Co۱۰-xFex, ۰≤ x ≤۷), thereafter characterized using various procedures. Magnetic measurements are conducted meticulously using the hysteresis curve and first-order reversal curve (FORC) techniques. Hysteresis curves demonstrate a consistent increase in saturation magnetization of Co۱۰-xFex MPs, ranging from around ۷۲ to ۱۷۳ emu/g as x rises from ۰ to ۷, alongside a non-monotonic fluctuation in coercivity, exhibiting maximum and minimum values of ۲۰۲ and ۹۲ Oe for x= ۱ and ۷, respectively. Simultaneously, FORC diagrams exhibit the multidomain behavior of the MPs, characterized by a restricted distribution of coercive fields, which is associated with intensified magnetostatic interactions at elevated Fe concentrations (x≥ ۳). The microwave absorption characteristics of Co۳Fe۷ alloy MPs are enhanced by adjusting their thickness between ۱.۴ and ۳.۰ mm, resulting in a minimum reflection loss of approximately –۵۰ dB at ۱۱.۷ GHz.

کلیدواژه ها:

CoFe alloy microparticles ، First-order reversal curve ، Coercive field ، Interaction field ، Multidomain state ، Microwave absorption properties