Undoped and magnesium-doped zinc oxide thin films were prepared by the sol–gel method. Results from X-ray diffraction indicated that the films exhibited a hexagonal wurtzite structure and were highly oriented along the [Formula: see text]-axis. The intensity of the (002) diffraction peak increased with increasing the Mg doping concentration. Also, Mg doping inhibited the growth of crystallite size which decreased from 46[Formula: see text]nm to 38[Formula: see text]nm with doping concentration. Morphological studies by atomic force microscopy (AFM) indicated the uniform thin film growth and the decreasing of grain size and surface roughness with Mg doping. Optical analysis showed that the average transmittance of all films was above 90% in the visible range and Mg doping has significantly enhanced the bandgap energy of ZnO. Two Raman modes assigned to [Formula: see text] and [Formula: see text] for the ZnO wurtzite structure were observed for all films. UV emission peak and three defect emission peaks in the visible region were observed by photoluminescence measurements at room temperature. The intensity ratio of UV emission to the visible emission increased with the Mg concentration. Photocurrent measurements revealed that all films presented the photoresponses with [Formula: see text]-type semiconducting behavior and their generated photocurrents were reduced by Mg doping. The prepared thin films of high quality with improved properties by Mg doping could be proposed to workers in the field of optoelectronic devices for using them as a strong candidate.

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Transparent zinc oxide (ZnO) thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations (0.3-1.2 M) using zinc acetate dehydrate [Zn(CH3COO)2•2H2O] as precursor and isopropanol and monoethanolamine (MEA) as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.

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The zircaloy-4 is an alloy of zirconium, which has a very weak thermal neutron absorption, satisfactory mechanical properties and good corrosion resistance at high temperature. For these reasons, zircaloy-4 is used as a material of cladding fuel rod of nuclear reactors. In this environment, it is submitted to different severe conditions of temperature and pressure. The objective of this work is to study the oxidation kinetics of zircaloy-4 in air by the X-ray diffraction technique. The experiments were realized in a "HTK1200" furnace installed as a sample holder in the diffractometer at different temperatures; 25˚C, 350˚C, 500˚C, 830˚C and 1000˚C. The results show that the monoclinic and the tetragonal phases are formed at 350˚C temperature. The volume fraction of these phases increased with the temperature until 1000˚C where the α phase disappears completely. For simulating the case of loss-of-coolant-accident (LOCA), we have done x-ray diffraction of Zry-4 samples water quenched at 1050˚C with different ageing times at this temperature. At 10 seconds and more, there is an important evolution of monoclinic and tetragonal zirconias, which leads to the degradation of zircaloy-4 properties.