This work is an original example to compare the results obtained after calcination of Al2O3hydroxides and oxidation of alumino-formers alloys. FTIR and XPS signatures were obtained for various oxidation temperatures and compared with those known from the literature about calcination of Al2O3precursors. The aim of this work is to evaluate the use of IR spectroscopy and XPS analysis to probe the structural varieties of Al2O3. For this objective, a study of the PM2000 oxidation at various temperatures was conducted by means of XRD, IR spectroscopy, XPS analysis, EDX analysis, and SEM observations. This allowed us to clearly differentiate the transition Al2O3from theα-Al2O3and, amongst the transition Al2O3, to differentiate the characteristic of the IR spectrum ofγ-δphases from that of theθphase.

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Zinc oxide (ZnO) thin films have been prepared by ultrasonic Spray pyrolysis (USP) technique using zinc acetate dihydrate dissolved in methanol, ethanol and deionized water. A number of techniques, including X‐ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, UV–visible, electrical resistivity, and photoluminescence (PL) were used to characterize the obtained ZnO thin films. The evolution of the preferred crystalline orientations in the ZnO films was systematically investigated. The PL measurements indicated that the as‐grown ZnO thin films showed UV and green emission bands when they were excited by a Hg arc lamp using 313 nm as the excitation source. A red‐shift in the near band edge (NBE) has been observed with the increase in the substrate temperature and has been attributed to the compressive intrinsic stress present in the films. It is confirmed that oxygen vacancy (VO) is the most important factor that causes the broad visible emission. Furthermore, the visible emission and electrical resistivity of ZnO thin films are found to be a function of porosity. Also, it has been interestingly found that the intensity of green emission at ∼2.5 eV remarkably increased when the obtained ZnO films were deposited at 320 °C. The reason might be the VO, intrinsic stress, surface‐to‐volume ratio and porosity in the sample increased at low substrate temperature. The resistivity follows the same behavior as the intensity of the green emission. We propose a new luminescence mechanism based on the recombination related to oxygen vacancies in Zn‐rich or stoichiometric conditions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)