X-ray detected ferromagnetic resonance techniques for the study of magnetization dynamics

TL;DR

This paper discusses the development and application of X-ray detected ferromagnetic resonance (XFMR) techniques, which utilize element-specific spectroscopy to study magnetization dynamics and spin interactions in magnetic materials.

Contribution

It introduces recent advancements in XFMR, including scattering techniques like DFMR and RFMR, for probing complex magnetic structures and their dynamic behaviors at GHz frequencies.

Findings

XFMR enables phase and amplitude measurement of magnetization precession.

X-ray scattering techniques reveal dynamics of chiral and multilayered magnetic materials.

Potential for high-density, low-energy magnetic data processing.

Abstract

Element-specific spectroscopies using synchrotron-radiation can provide unique insights into materials properties. The recently developed technique of X-ray detected ferromagnetic resonance (XFMR) allows studying the magnetization dynamics of magnetic spin structures. Magnetic sensitivity in XFMR is obtained from the X-ray magnetic circular dichroism (XMCD) effect, where the phase of the magnetization precession of each magnetic layer with respect to the exciting radio frequency is obtained using stroboscopic probing of the spin precession. Measurement of both amplitude and phase response in the magnetic layers as a function of bias field can give a clear signature of spin-transfer torque (STT) coupling between ferromagnetic layers due to spin pumping. Over the last few years, there have been new developments utilizing X-ray scattering techniques to reveal the precessional magnetization dynamics of ordered spin structures in the GHz frequency range. The techniques of diffraction and reflectometry ferromagnetic resonance (DFMR and RFMR) provide novel ways for the probing of the dynamics of chiral and multilayered magnetic materials, thereby opening up new pathways for the development of high-density and low-energy consumption data processing solutions.