# X-ray reflectivity with a twist: quantitative time-resolved X-ray reflectivity using monochromatic synchrotron radiation

## TL;DR

This paper presents an advanced time-resolved X-ray reflectivity method using monochromatic synchrotron radiation, enabling high temporal resolution and improved data quality for studying thin film dynamics.

## Contribution

The authors introduce a novel XRR technique combining a polycapillary optic and sample rotation to separate diffuse scattering, enhancing spectral quality and temporal resolution.

## Key findings

- Achieved 10 ms temporal resolution in XRR measurements.
- Successfully measured interdiffusion activation energy in Al/Ni multilayers.
- Demonstrated improved spectral quality over previous methods.

## Abstract

We have developed an improved method of time-resolved x-ray reflectivity (XRR) using monochromatic synchrotron radiation. Our method utilizes a polycapillary x-ray optic to create a range of incident angles and an area detector to collect the specular reflections. By rotating the sample normal out of the plane of the incident fan, we can separate the surface diffuse scatter from the reflectivity signal, greatly improving the quality of the XRR spectra compared to previous implementations. We demonstrate the time-resolved capabilities of this system, with temporal resolution as low as 10 ms, by measuring XRR during the annealing of Al/Ni nano-scale multilayers and use this information to extract the activation energy for interdiffusion in this system.