This article deals with an investigation of the effect of oxygen content on optical and structural properties of ZnO films. Zinc oxide films were deposited with the DC reactive magnetron sputtering process on Si(100) and glass substrates. ZnO films were elaborated at different oxygen flow rates from (O 2 ) 12 to 35 sccm. The evolution of optical and structural properties as a function of O 2 was investigated by X-ray diffraction, Profilometer, Field Emission Scanning Electron Microscopy (FESEM) and ultraviolet-visible. By increasing O 2 , the crystallite size increases from 20 to 27 nm, which leads to an enlargement in the ZnO band gap from 3.18 to 3.30 eV. At 30 sccm of O 2 , the films present a significant improvement in the band gap (3.30 eV). The results reveal that with increasing O 2 , all films show a high crystallinity in the wurtzite phase and present a (002)ZnO preferential orientation along the c-axis. ZnO exhibited a good self-texture.
Ti-stabilized austenitic stainless steel was carburized in sodium containing a high carbon activity at three different temperatures, 500 °C, 600 °C, and 650 °C during 1000 hours and 5000 hours. The carbon profile, the carbide volume fraction, and the lattice parameter evolution as fonction of depth were determined using high-energy X-ray diffraction and electron probe microanalysis. At 650 °C and 600 °C, the carbon precipitated as M 23 C 6 and M 7 C 3 carbides in the sample. The volume fraction of M 7 C 3 carbides was lower than predicted by thermodynamic equilibrium using Thermo-Calc software ® . At 500 °C, carbides almost did not form in the steel. Instead, high carbon supersaturation of the austenitic matrix occurred. Both results demonstrate that the carburiz.ation profile was strongly influenced by the kinetics of carbide formation at temperatures lower than 650 °C. High-energy X-ray diff raction measurements demonstrated that the austenite and carbide lattice parameters evolved along the carbon profile. Both measured lattice parameter profi les of austenite and M 23 C 6 carbide were compared to the ones predicted from chemical changes of austenite and carbides.
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