Spin precession mapping at ferromagnetic resonance via nuclear resonant scattering

TL;DR

This study uses nuclear resonant scattering of synchrotron radiation to map spin precession at ferromagnetic resonance in thin magnetic films, providing a new method for high-resolution magnetization dynamics analysis.

Contribution

It introduces a novel approach combining nuclear resonant scattering with ferromagnetic resonance theory to determine spin precession shapes in layered structures.

Findings

Determined the shape of the spin precession cone.

Demonstrated high depth resolution in magnetization dynamics.

Established a new method for analyzing layered magnetic structures.

Abstract

We probe the spin dynamics in a thin magnetic film at ferromagnetic resonance by nuclear resonant scattering of synchrotron radiation at the 14.4 keV resonance of $^{57}$Fe. The precession of the magnetization leads to an apparent reduction of the magnetic hyperfine field acting at the $^{57}$Fe nuclei. The spin dynamics is described in a stochastic relaxation model adapted to the ferromagnetic resonance theory by Smit and Beljers to model the decay of the excited nuclear state. From the fits of the measured data the shape of the precession cone of the spins is determined. Our results open a new perspective to determine magnetization dynamics in layered structures with very high depth resolution by employing ultrathin isotopic probe layers.