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F Boscherini

Publications and source records attributed to F Boscherini.

At least 19 recordsLinked to original sources
PubMed2006

Iron oxidation, interfacial expansion, and buckling at the Fe/NiO(001) interface.

In order to provide a structural basis for a physical understanding of exchange bias in metal/magnetic-oxide interfaces, we have determined the structure of the Fe/NiO(001) interface by means of x-ray absorption spectroscopy and ab initio density functional theory calculations. A Fe-Ni alloyed phase on top of an interfacial FeO planar layer is formed. The FeO layer exhibits a 7% expanded interlayer distance and a 0.3 A buckling; its presence is predicted to increase the spin magnetic moment of the interface Fe atoms by 0.6 mu(B), compared to the ideally abrupt interface.

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PubMed2002

New opportunities in trace elements structural characterization: high-energy X-ray absorption near-edge structure spectroscopy.

Garnets in lower crustal mafic and ultramafic rocks usually contain rare-earth elements (REE) in trace concentrations. Direct characterization of REE at trace levels in natural garnets is not available in the literature because of the difficulty of obtaining structural information by means of conventional diffraction methods. Here, the characterization of Nd at trace levels (176-1029 p.p.m.) in a set of natural garnets performed by means of Nd K-edge X-ray absorption near-edge structure spectroscopy is presented, showing the capability of high-energy XANES for REE in trace structural determinations.

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PubMed1998

Anomalous wide-angle X-ray scattering apparatus on the GILDA beamline at the ESRF.

The experimental apparatus for anomalous wide-angle X-ray scattering (AWAXS) on the GILDA beamline at the ESRF is described. The main features are the high beam stability and reproducibility which allow anomalous scattering effects to be resolved also on dilute elements, the large spectral range which allows AWAXS experiments at the K edges of heavy elements, and the use of a high-efficiency detection system. The apparatus has been tested in extreme conditions by performing AWAXS experiments at the Eu K edge in Eu-doped Sr metaphosphate glasses.

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PubMed1996

X-ray Optics of a Dynamical Sagittal-Focusing Monochromator on the GILDA Beamline at the ESRF.

The performance of a dynamical sagittal-focusing monochromator for hard X-rays is described. It consists of a flat first crystal and a diamond-shaped ribbed second crystal which is clamped by its central rib and dynamically bent by applying a force on its two apices. The system has proved to perform very well on the GILDA beamline at the ESRF. The horizontal acceptance varies with energy and with focusing geometry as predicted theoretically; the total available horizontal fan of radiation (3.6 mrad) is in fact collected in the 1:3 geometry. The system is routinely run in a dynamical focusing mode for XAFS spectroscopy in the energy range 5-30 keV with Si(311) crystals, with a constant spot size FWHM ~1 mm on the sample and without degradation of energy resolution or reproducibility. Using simple geometrical considerations we calculate the variations of the horizontal profile of the reflected beam during rocking-curve scans in different focusing geometries and find them in agreement with observed ones. Not only is this is a practical aid in alignment but it illustrates the X-ray optics of sagittal focusing in an elegant way.

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