Publications by authors named "Xavier Biquard"

Micro-Laue diffraction has been used to record cross-section profiles on a quasi-lattice-matched HgCdTe/CdZnTe heterostructure as a function of the stress induced by a flexion machine. The heterostructure may be decomposed into four different regions according to depth. Sufficiently far from the interface, the CdZnTe substrate is undisturbed by the HgCdTe layer, while the region situated 10 µm beneath the interface presents an in-plane lattice parameter adjustment to the +0.

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The structural and optical properties of axial GaN/InGaN/GaN nanowire heterostructures with high InN molar fractions grown by molecular beam epitaxy have been studied at the nanoscale by a combination of electron microscopy, extended x-ray absorption fine structure and nano-cathodoluminescence techniques. InN molar fractions up to 50% have been successfully incorporated without extended defects, as evidence of nanowire potentialities for practical device realisation in such a composition range. Taking advantage of the N-polarity of the self-nucleated GaN NWs grown by molecular beam epitaxy on Si(111), the N-polar InGaN stability temperature diagram has been experimentally determined and found to extend to a higher temperature than its metal-polar counterpart.

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Temperature dependent phase transitions of compounds (GeTe)(n)Sb(2)Te(3) (n = 6, 12, 15) have been investigated by in situ microfocus Laue diffraction. Diffusion processes involving cation defect ordering at ~300 °C lead to different nanostructures which are correlated to changes of the thermoelectric characteristics.

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A new set-up is reported of an indirect cryogenic cooling system for a double-crystal monochromator which runs on the BM30b/FAME beamline at the ESRF (Grenoble, France). This device has been conceived to limit the vibrations on the first diffracting crystal and to maintain it at a constant temperature. These points are crucial for maximizing the beamline stability.

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