Magnetic resonance studies of the fundamental spin-wave modes in individual submicron Cu/NiFe/Cu perpendicularly magnetized disks

Spin-wave spectra of perpendicularly magnetized disks consisting of a 100 nm permalloy layer sandwiched between two Cu layers of 30 nm are measured individually by a magnetic resonance force microscope. Using 3D micromagnetic simulations, it is demonstrated that, for submicron-size diameters, the lowest energy spin-wave mode of the saturated state is not spatially uniform, but rather is localized at the center of the Py/Cu interfaces in the region of the minimum demagnetizing field.