Chirp Spectroscopy Applied to the Characterization of Ferromagnetic Resonance in Magnetic Tunnel Junctions

Magnetic tunnel junction (MTJ) devices find use in several applications based on the exploitation of the spin-transfer torque phenomenon. The ferromagnetic resonance (FMR) curve is a key characteristic of any MTJ. It is usually characterized both experimentally and numerically by performing a lot of measurements of the magnetic response to a sinusoidal field or current. Here, we propose the use of a chirp signal as excitation signal to reconstruct the FMR curve with a single measurement/simulation. A micromagnetic comparison of the proposed method with the traditional one is shown. © 1965-2012 IEEE.