Observation of localized ferromagnetic resonance in a continuous ferromagnetic film via magnetic resonance force microscopy

TL;DR

This study demonstrates localized ferromagnetic resonances in a thin permalloy film using magnetic resonance force microscopy, revealing multiple confined modes influenced by the magnetic field of the MRFM tip.

Contribution

First observation of localized ferromagnetic resonance modes in a continuous film using MRFM, supported by micromagnetic simulations.

Findings

Multiple localized resonance modes observed at small probe-sample distances.

Resonance modes are stabilized by the dipolar field of the MRFM tip.

Micromagnetic simulations confirm the experimental identification of modes.

Abstract

We present Magnetic Resonance Force Microscopy (MRFM) measurements of Ferromagnetic Resonance (FMR) in a 50 nm thick permalloy film, tilted with respect to the direction of the external magnetic field. At small probe-sample distances the MRFM spectrum breaks up into multiple modes, which we identify as local ferromagnetic resonances confined by the magnetic field of the MRFM tip. Micromagnetic simulations support this identification of the modes and show they are stabilized in the region where the dipolar tip field has a component anti-parallel to the applied field.