Ferromagnetic Resonance in Electroplated CuBe/FeCoNi and Amorphous CoFeSiB Wires

Abstract

Ferromagnetic wires are widely used in microwave technologies. In this work, impedance studies were carried out in a wide range of microwave frequencies (from 0.1 to 20 GHz). By compensating the parameter $\boldsymbol S_{11}$ for the length of the adapter and the holder, it was possible to ensure the inductive nature of the wire impedance up to the frequency of 14 GHz. As a result, the wire response was described as a lossy inductance, and the inductive resistance of which changes by the $\Delta {X}$ value and the active resistance by $\Delta $ R value under the influence of an external constant magnetic field. We were able to approximate $\Delta $ X and $\Delta $ R changes with the real and imaginary parts of the diagonal component of the magnetic susceptibility tensor, obtained from the Landau–Lifshitz equation with a Gilbert damping term for ferromagnetic resonance (FMR), and determine the FMR parameters in the microwave region. It was also possible to separate the FMR region from the region of such microwave absorption phenomena as magnetoimpedance. An optimized system based on the vector network analyzer ZVA-67 was designed and tested. It allowed to determine experimentally the parameters of magnetoimpedance and FMR of the electroplated FeCoNi/CuBe and rapidly quenched CoFeSiB amorphous wires measured by the same device and in the same configuration in a single-frequency scan. A prototype of the magnetic field sensor has been proposed and tested.