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arXiv · 2402.06115

Small-angle X-ray resonant magnetic scattering at the Co M$_{2,3}$ and L$_3$ edges observed with photoemission electron microscopy

Alexis Wartelle·Marisel Di Pietro Martínez·Olivier Fruchart·Philippe David·Guillaume Beutier
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Abstract

X-ray magnetic circular dichroism is an efficient contrast mechanism allowing for a direct sensitivity to magnetization. Combined with an imaging technique such as photoemission electron microscopy, it has been successfully applied to high-resolution investigations of ferromagnetic thin films but also of three-dimensional systems thanks to the transmission-type contrast in their shadow. Our focus in this work is the wave-optics scattering pattern that can be observed near such a shadow's rim. Taking advantage of non-uniform magnetic states present in near-micron-size Co$_{1-x}$Gd$_x$ beads, we first show how X-ray resonant magnetic scattering affects the Fresnel diffraction at the Co L$_3$ edge. In order to confirm this observation, we then turn to the Co M$_{2,3}$ edges. There, we measure magnetic scattering patterns with a significantly increased spatial extent (due to the larger wavelength), despite the signal's weakness. The patterns' origin is supported by a comparison between our experimental data and a simple analytical model, then numerical simulations.

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Alexis Wartelle, Marisel Di Pietro Martínez, Olivier Fruchart, Philippe David, Guillaume Beutier. 2024-02-09. Small-angle X-ray resonant magnetic scattering at the Co M$_{2,3}$ and L$_3$ edges observed with photoemission electron microscopy. https://arxiv.org/abs/2402.06115

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