Ferromagnetic Resonance (FMR)

Ferromagnetic resonance (FMR) is used to probe the magnetisation dynamics of magnetic thin films and calculate dynamic magnetic parameters such as Gilbert damping (α), saturation magnetisation (MS), and inhomogeneous linewidth (dH). We have a home made co-planer waveguide based broad-band FMR set-up, working in the range of 100 MHz to 20 GHz (Figure 1). Co-planar waveguide utilizes a two-port transmission line and provides access to a broad range of frequency for measurements comparatively to conventional cavity based FMR. In FMR measurements, we uses the signal generator as a RF source and connects it to one port of CPW then transmitted signal is detected by a microwave diode and lock-in amplifier through the second port, the sweeping static field is provided by electromagnet and modulated with a small frequency sine waves to provide reference signal to the lock-in amplifier. Figure 2 shows a observed FMR spectra for a fixed frequency. We are interested in studying several novel phenomenon using FMR measurements like spin pumping, spin Hall effect (SHE) and inverse spin Hall effect (ISHE).