Zainab T Hussain, Wasna’a M Abdulridha, Murooj A Abood, Farqad Saeed,
Volume 23, Issue 1 (3-2026)
Abstract
In this study, RF magnetron sputtering was employed to create titanium dioxide (TiO2) thin films doped with zirconium oxide (ZrO2) (TZO) onto quartz and silicon substrates at 100oC for the purpose of evaluating the effect of ZrO2 doping on the microstructural, electrical, optical and gas sensing properties of the TiO2 films. Different doping concentrations (0.0, 2.0 and 4.0 wt.%) were used to compare performances of the films with a thickness ranging between 147 nm to 178 nm. Structural and surface morphology characterizations of the prepared films were carried out by X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. The surface morphology of the prepared TZO films showed a gradual reduction in the grain size while the doping concentration increased. The optical characteristics of the films also exhibited an increasing trend in the optical band gap with the rising ZrO2 concentration. TiO2 films showed an n-type conductivity as confirmed by Hall's measurement. The results of the gas sensing experiments revealed that the sensitivity of the TZO films for the detection of ethanol vapor increased with an increase in the concentration of ZrO2 dopant. Therefore, TZO film with 4.0 wt.% of ZrO2 could be used as an effective sensor for detecting ethanol vapor.
Ehsan Bazzaz, Majid Alitavoli, Mehdi Yarmohammad Tooski, Mohammad Mehdi Bazzaz,
Volume 23, Issue 2 (6-2026)
Abstract
Improvement of the mechanical properties of the coated surfaces was the matter of significant researches for a long time. A lot of physical and chemical operations were applied and examined on the coating surfaces successfully, but the effect of the mechanical treatments was not widely investigated. In this paper, the effect of a surface mechanical treatment on the micro coating layer has been studied and investigated. For this purpose, the necessary conditions have been created for implying impact to the coating surface. A setup of gas gun facility with well-designed and prepared projectiles are used to strike the sample surface with different speeds. A significant number of impacts have been inflicted on the test sample of the spade drill insert cutting tool. The consequence of this process is the change in crystal structure of the coating layer, which shows that under the created conditions, the crystal structure was not destroyed and instead getting compacted so that the size of the crystal grains has been reduced and considerably refined. Subsequent studies using electron microscopy have led to the measurement of the average size of the crystalline grains before and after impacts. Obviously, a significant effect has been observed and a meaningful trend has been seen for this change in the form of a linear relationship. The main result is that about 4% reduction in the average grain size happens when the impact speed changes by 10m/s. In this way, the principal basis for the use of this surface treatment in improving the surface properties of the micro coating layers is provided. This leads to the application of such treatments as an industry process for improvement of thin coating mechanical properties.
