Electrically detected ferromagnetic resonance

We study the magnetoresistance properties of thin ferromagnetic $CrO2$ and $Fe3O4$ films under microwave irradiation. Both the sheet resistance $ρ$ and the Hall voltage $VHall$ characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonance (EDFMR) signals closely match the conventional FMR, measured simultaneously, in both resonance fields and line shapes. The sign and the magnitude of the resonant changes $Δρ∕ρ$ and $ΔVHall∕VHall$ can be consistently described in terms of a Joule heating effect. Bolometric EDFMR thus is a powerful tool for the investigation of magnetic anisotropy and magnetoresistive phenomena in ferromagnetic micro- or nanostructures.