High frequency losses of ferromagnetic wires near the gyromagnetic resonance

Co-based amorphous glass-covered microwires have been manufactured with inner metal diameter ranging from 4.5 to 12 μm and constant total diameter of 17.5 μm. The parallel permeability of these wires has been measured in the 10 MHz to 6 GHz frequency range. It is shown that for the thinner core diameters, the high frequency features are well described using a conventional gyromagnetic model and the measured values of the anisotropy field. For the thicker core diameters, it appears that the measured anisotropy field does not account for the high frequency behavior