FMR study on patterned and unpatterned magnetic thin films

Abstract Ferromagnetic resonance linewidth, Δ H , of polycrystalline Ta50 A/Ni 80 Fe 20 /Ta50 A films and patterned sandwich structures (NiFeCo60 A/Cu30 A/NiFeCo30 A) of submicron size was studied. Δ H ∥ is found to be in the range of 32–41 Oe for single-layer films with thickness larger than 100 A, which seems to be mainly due to intrinsic damping. For films thinner than 100 A, Δ H ∥ increases sharply, approaching a peak around 50 A and then drops. For patterned films, Δ H ∥ is found to increase with the decrease of element size. Magnetization measurements show a similar trend between coercivity and the element size.