Vector network analyzer ferromagnetic resonance with field differential detection

摘要

Ferromagnetic resonance (FMR) is the most commonly used measurement for characterizing magnetization dynamics in the microwave frequency range. To explore the frequency dependence of magnetization dynamics, a vector network analyzer ferromagnetic resonance (VNA-FMR), which can perform a broadband FMR measurement, has been used. However, the VNA-FMR measures the S-parameter that contains the FMR signal of interest under a constant bias field, thus its signal-to-noise ratio (SNR) is limited by the sensitivity fluctuation of the VNA, i.e. low frequency components of the trace noise. Another problem identified in this work is that the analysis of the measurement data taken by the VNA-FMR for estimating the Gilbert damping parameter still follows the conventional algorithm based on the spectral linewidth, which we found is not optimum for the VNA-FMR.