@article {Sertsu2015,
	title = {Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges},
	journal = {Appl. Opt.},
	volume = {54},
	number = {35},
	year = {2015},
	month = {Dec},
	pages = {10351–10358},
	publisher = {OSA},
	abstract = {Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d$=$16.4&\#x2009;&\#x2009;nm, number of bilayers N$=$25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms&\#x2019; interactions on optical responses of Si and Mo layers are discussed.},
	keywords = {Buried interfaces, extreme ultraviolet (EUV), multilayers, soft x-rays, Space optics, Synchrotron radiation, X-rays},
	doi = {10.1364/AO.54.010351},
	url = {http://ao.osa.org/abstract.cfm?URI=ao-54-35-10351},
	author = {M. G. Sertsu and M. Nardello and A. Giglia and A. J. Corso and C. Maurizio and L. Juschkin and P. Nicolosi}
}
@article {Rossi2015,
	title = {Phase measurement of soft x-ray multilayer mirrors},
	journal = {Opt. Lett.},
	volume = {40},
	number = {19},
	year = {2015},
	month = {Oct},
	pages = {4412–4415},
	publisher = {OSA},
	abstract = {We propose a new model enabling the extraction of the phase of a multilayer mirror from photocurrent measurements in the soft x rays. In this range, the effects of the mean free path of the electrons inside the stack can no longer be neglected, which prevents the phase reconstruction by conventional photocurrent measurements. The new model takes into account this phenomenon and thus extends up to the x rays the applicability range of the technique. This approach has been validated through a numerical and experimental study of chromium/scandium multilayers used near 360&\#xA0;eV. To our knowledge, this work constitutes the first measurement of the phase of a multilayer mirror in the soft x-ray range.},
	keywords = {multilayers, Phase measurement, X-ray mirrors},
	doi = {10.1364/OL.40.004412},
	url = {http://ol.osa.org/abstract.cfm?URI=ol-40-19-4412},
	author = {Sèbastien de Rossi and Charles Bourassin-Bouchet and Evgueni Meltchakov and Angelo Giglia and Stefano Nannarone and Franck Delmotte}
}
@article {Yuan2014,
	title = {Co/Mo2C multilayer as X- ray mirror: Optical and thermal performances},
	journal = {Physica status solidi. B, Basic research},
	volume = {251},
	year = {2014},
	pages = {803–808},
	publisher = {Wiley-VCH-Verl..},
	address = {Weinheim},
	abstract = {We combined soft X-ray reflectivity (SXR) and X-ray standing-wave-enhanced fluorescence to study the optical performance and the thermally-induced interface behavior of Co/Mo2C nanometric multilayers, designed to work in the soft X-ray range close to the Co L3 absorption edge. Grazing X-ray reflectivity measurements were performed at 0.154nm (Cu K line) and at two wavelengths in the soft X-ray range, 1.59 and 1.33nm, close to and far from the Co L3 edge. In the fluorescence experiment the intensity of the Co L emission was measured by the standing-wave method within a Co/Mo2C stack. We found that the Co/Mo2C multilayers present good optical performance in the soft X-ray range up to 600 degrees C annealing temperature. Indeed, the reflectivity value in the soft X-ray range at a grazing angle of 11 degrees is 25% for the as-deposited sample, then slightly varies with annealing and is still 20% after annealing at 600 degrees C. This demonstrates the good thermal stability of the Co/Mo2C multilayer. We used a simplified two-layer model and modified optical indices of the Co nanofilms to fit the experimental X-ray reflectivity curves. The same modified values of the optical indices are used to fit the X-ray standing-wave curves, confirming the usefulness of the model of the stack.},
	keywords = {CO, Mo2C, multilayers, optical properties, standing waves, X-ray mirrors},
	issn = {0370-1972},
	doi = {10.1002/pssb.201350082},
	author = {Yuan, Yanyan and Le Guen, Karine and Andre, Jean-Michel and Wang, Zhanshan and Li, Haochuan and Zhu, Jingtao and Meny, Christian and Giglia, Angelo and Nannarone, Stefano and Jonnard, Philippe}
}
