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This contribution investigates the phase composition of CrN and CrAlN coatings by in-situ high temperature synchrotron radiation (SR-XRD), with the coatings deposited on steel substrate by closed field unbalance magnetron sputtering. Rietveld refinement on the SR-XRD spectra indicated CrN as the major phase, over the temperature range of 25 °C – 700 °C, for both coatings. At the high temperature of 700 °C, a Cr 2 N phase was observed in the CrN coating while the CrAlN coating also had a Cr phase. Williamson–Hall plots, from the refined data, afforded estimating variations of the strain and crystallite size of the major phase, up to 700 °C. The crystallite size (10 nm) for the CrAlN coating, at 25 °C, agrees very well with previous GI-XRD and TEM results obtained at room temperature Li et al. (2012). [ABSTRACT FROM AUTHOR]

Abstract: New cobalt-based metal oxide thin films (MxCoyOz with M=Mn, Cu, Ni) have been deposited on commercial aluminum and glass substrates using sol–gel dip-coating method. The as-deposited films were characterized by a wide range of complementary techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), spectrophotometry and nanoindentation techniques. A light absorption study for coatings on glass substrates within a wavelength range of 300–1100nm was also conducted. Topographical and morphological investigations showed the presence of nano-sized, grain-like particles in the copper–cobalt oxide coatings, which consequently had the roughest surface among the three coatings. All coatings on glass substrate exhibited higher absorption of ultraviolet (UV) light compared to visible light, while coatings on aluminum substrate generally had low reflectance (<50%) of UV light, moderate reflectance (<80%) of visible light and high reflectance (up to 100%) of infrared light. Implications of optical properties as a function of film thickness controlled by dip-heating cycles were discussed. The elastic modulus (E) and hardness (H) of thin film samples compared with stand‐alone commercial aluminum substrate were also measured. [Copyright &y& Elsevier]

This contribution investigates the effect of the addition of the Hubbard U parameter on the electronic structural and mechanical properties of cubic ( C -type) lanthanide sesquioxides (Ln 2 O 3 ). Calculated Bader's charges confirm the ionic character of Ln O bonds in the C -type Ln 2 O 3 . Estimated structural parameters (i.e., lattice constants) coincide with analogous experimental values. The calculated band gaps energies at the U eff of 5 eV for these compounds exhibit a non-metallic character and U eff of 6.5 eV reproduces the analogous experimental band gap of cerium sesquioxide Ce 2 O 3 . We have thoroughly investigated the effect of the O/Ce ratios and the effect of hafnium (Hf) and zirconium (Zr) dopants on the reduction energies of CeO x configurations. Our analysis for the reduction energy of CeO 2 , over a wide range of temperatures displays that, shuffling between the two +4 and +3 oxidation states of Ce exhibit a temperature-independent behaviour. Higher O/Ce ratios necessitate lower reduction energies. Our results on Ce Hf Zr O alloys are in reasonable agreements with analogous fitted values pertinent to lowering reduction energies and shrinkage in lattice parameters when contrasted with pure CeO 2 . Structural analysis reveals that Hf and Zr atoms in the solid solution are shifted towards the nearest vacancies upon reduction. It is hoped that values provided herein to shed an atomic-base insight into the reduction/oxidation thermodynamics of increasingly deployed catalysts for environmental applications. [ABSTRACT FROM AUTHOR]