Figure 6
From: Engineering optical mode ferromagnetic resonance in FeCoB films with ultrathin Ru insertion
The magnetic field dependence of permeability spectra along EA direction.
The FMR frequency peak in FeCoB single layer increases monotonically with the increase of magnetic field due to its acoustic mode FMR (a–c). However, the FeCoB/Ru/FeCoB trilayer exhibits three possible FMR mode: optical only (d), acoustic only (f), or double mode (e), depending on the magnetic configuration at the corresponding external magnetic field.
