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Sm0.5Ca0.5MnO3 thermochromic thin films were synthesized using dc reactive magnetron co-sputtering and subsequent annealing in air. The film structure was studied by x-ray diffraction analysis. To validate the thermochromic potentiality of Sm0.5Ca0.5MnO3, electrical resistivity and infrared transmittance spectra were recorded for temperatures ranging from 77 K to 420 K. The temperature dependence of the optical band gap was estimated in the near infrared range. Upon heating, the optical transmission decreases in the infrared domain showing a thermochromic effect over a wide wavelength range at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Orientation imaging techniques based on electron backscattering diffraction (EBSD) and convergent beam electron diffraction (CBED) pattern acquisition carried out respectively in the scanning electron microscope (SEM) and in the transmission electron microscope (TEM) were used to characterise the orientation of crystals in two highly oriented diamond (HOD) films with different thicknesses. The substrate surface modification has been also investigated by EBSD. The films were synthesised on Si(100) in a microwave plasma chemical vapor deposition (MPCVD) reactor where nucleation is initiated via an in situ pretreatment consisting in a carburization step followed by a bias enhanced nucleation (BEN). For the thin film EBSD allowed to highlight the presence of alpha-SiC on the silicon substrate as well as to evaluate their epitaxial relationship. The TEM-based system allowed to obtain more accurate misorientation data of the fine grained diamond structure corresponding to the first stages of growth. For the thicker film, EBSD was used to determine the mosaicity at the surface. [Copyright &y& Elsevier]

Highly oriented diamond (HOD) films were deposited on Si (0 0 1) substrates by the microwave plasma assisted chemical vapor deposition technique using the bias enhanced nucleation (BEN) step. The formation of HOD films is often linked to the presence of few parts per million of nitrogen which stabilizes the texture but deteriorates the chemical quality of the film. In this study, we show that carbon monoxide can be used without nitrogen addition to conserve the 〈0 0 1〉 texture and to promote the {1 0 0} facet extension on the top of the diamond film. After a nucleation step carried out by the BEN technique, and after a subsequent growth time limited to 30 min in a CH4/H2 gas mixture avoiding the coalescence step, HOD films were synthesized using CH4/H2, CO/H2 and N2/CH4/H2 gas mixtures for a growth time fixed to 10–14 h. The effect of carbon monoxide or nitrogen on the morphologies and the texture of the diamond films is discussed from the results of scanning electron microscopy and the texture measurements performed by X-ray diffraction. [Copyright &y& Elsevier]