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arXiv · 1511.01739

X-ray fluorescence induced by standing waves in the grazing-incidence and grazing-exit modes: study of the Mg--Co--Zr system

Yuchun Tu·Yanyan Yuan·Karine Le Guen·Jean-Michel André·Jingtao Zhu·Zhanshan Wang·Françoise Bridou·Angelo Giglia·Philippe Jonnard
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Abstract

We present the characterization of Mg-Co-Zr tri-layer stacks by using x-ray fluorescence induced by x-ray standing waves, both in the grazing incidence (GI) and grazing exit (GE) modes. The introduction of a slit in the direction of the detector improves the angular resolution by a factor 2 and significantly the sensitivity of the technique for the chemical characterization of the buried interfaces. By observing the intensity variations of the Mg Kalpha and Co Lalpha characteristic emissions as a function of the incident (GI mode) or detection (GE mode) angle, we show that the interfaces of the Si/[Mg/Co/Zr] x30 multilayer are abrupt, whereas in the Si/[Mg/Zr/Co] x30 multilayer a strong intermixing occurs at the Co-on-Zr interfaces. The explanation of this opposite behaviour of the Co-on-Zr and Zr-on-Co interfacesis given by the calculation of the mixing enthalpies of the Co-Mg, Co-Zr and Mg-Zr systems, which shows that the Co-Zr system presents anegative value and the two others positive values. Together with the difference of the surface free energies of Zr and Co, this leads us to consider the Mg/Zr/Co system as aMg/Co x Zr y bi-layer stack, with x/y estimated around 3.5.

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Yuchun Tu, Yanyan Yuan, Karine Le Guen, Jean-Michel André, Jingtao Zhu, Zhanshan Wang, Françoise Bridou, Angelo Giglia, Philippe Jonnard. 2015-11-05. X-ray fluorescence induced by standing waves in the grazing-incidence and grazing-exit modes: study of the Mg--Co--Zr system. https://doi.org/10.1107/s1600577515016239

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