# Extracting the Dynamic Magnetic Contrast in Time-Resolved X-ray Transmission Microscopy

## TL;DR

This paper demonstrates a method to measure element-specific dynamic magnetic contrast in time-resolved X-ray transmission microscopy, enabling detailed analysis of magnetic excitations with high spatial and temporal resolution.

## Contribution

It introduces new techniques to isolate dynamic magnetic contrast in time-resolved STXM using XMCD, and quantifies phase and precession angles at microwave frequencies.

## Key findings

- Dynamic contrast behaves as the XMCD effect.
- Phase and precession angle can be quantified.
- Method works for homogeneous and inhomogeneous excitations.

## Abstract

Using a time-resolved detection scheme in scanning transmission X-ray microscopy (STXM) we measured element resolved ferromagnetic resonance (FMR) at microwave frequencies up to 10\,GHz and a spatial resolution down to 20\,nm at two different synchrotrons. We present different methods to separate the contribution of the background from the dynamic magnetic contrast based on the X-ray magnetic circular dichroism (XMCD) effect. The relative phase between the GHz microwave excitation and the X-ray pulses generated by the synchrotron, as well as the opening angle of the precession at FMR can be quantified. A detailed analysis for homogeneous and inhomogeneous magnetic excitations demonstrates that the dynamic contrast indeed behaves as the usual XMCD effect. The dynamic magnetic contrast in time-resolved STXM has the potential be a powerful tool to study the linear and non-linear magnetic excitations in magnetic micro- and nano-structures with unique spatial-temporal resolution in combination with element selectivity.