Kossel interferences of proton-induced X-ray emission lines in periodic multilayers

TL;DR

This study demonstrates the observation of Kossel interferences in proton-induced X-ray emissions from a multilayer, using measurements near the Bragg angle, supported by a reciprocity theorem-based model, aiding nanolayer analysis.

Contribution

It introduces the first observation of proton-induced Kossel interferences in multilayers and validates a model for analyzing multilayer structures using these interferences.

Findings

Kossel interferences observed in proton-induced X-ray emissions.

Good agreement between experimental data and reciprocity theorem-based model.

Potential application in nanometer-thick layer and interface characterization.

Abstract

The Kossel interferences generated by characteristic x-ray lines produced inside a periodic multilayer have been observed upon proton irradiation, by submitting a Cr/B4C/Sc multilayer stack to 2 MeV protons and observing the intensity of the Sc and Cr K$\alpha$ characteristic emissions as a function of the detection angle. When this angle is close to the Bragg angle corresponding to the emission wavelength and period of the multilayer, an oscillation of the measured intensity is detected. The results are in good agreement with a model based on the reciprocity theorem. The combination of the Kossel measurements and their simulation, will be a useful tool to obtain a good description of the multilayer stack and thus to study nanometer-thick layers and their interfaces.