Development of Ferromagnetic Resonance System for Ultra-Low Temperature

The ferromagnetic resonance (FMR) including inverse spin hall effect (ISHE) by spin pumping is a useful method to analyze the spin dynamics of ferromagnetic material and the spin-charge conversion of ferromagnet/normal metal heterostructure. For localization of the ISHE-FMR system, we have developed a customizable ISHE-FMR system. The developed ISHE-FMR system can simultaneously measure the ISHE voltage and FMR signal in the various range of temperature (4 similar to 300 K). From this ISHE-FMR system, we measured the FMR derivative absorption signals and ISHE voltage of molecule-based ferromagnetic insulator (Cr-PBA, Tc = 220 K) and Co thin film. And we show the design and manufacture process of ISHE-FMR system briefly, and discuss the Gilbert damping constant of all the test samples compared with reference value.