Papers by Keyword: Coating Layers

Abstract: ZnO thin films is a kind of very potential semiconductor materials, due to their excellent chemical, electrical and optical properties. The effects of annealing temperature and coating layers on properties of ZnO thin films prepared by sol-gel immerse technique is studied in this work. The structure properties and optical properties were investigated by XRD, SEM and UV-Vis spectrophotometry respectively. It is found that the thin films were composed of better hexagonal wurtzite crystals with the c-axis preferred orientation by thermal annealing 550°C. With coating layers increasing from 2 layers to 8 layers, the intensity for all diffraction peaks were increased gradually, and the crystallite size of ZnO thin films is slightly increased. The transmittance of prepared thin films is over 80% in the visible-near IR region from 460 nm - 800 nm.

Abstract: The paper presents a vibroacoustic method to determining the stiffness of coated steel with various materials such as metal oxides, metallic paints, polymers etc and Young's modulus for coating materials. The method consists in measuring the dynamic response of the steel in the form of a rectangular bar subjected to external impulse. One of the latest non-destructive experimental techniques in this field is based on the analysis of vibrating signal response recorded with a condenser microphone. A Fast Fourier Transform algorithm is used for processing the sampled signals. Knowing the mechanical properties of steel plates prior to coating with metal oxides, and determining the same properties after coating, can be obtained the mechanical properties of metal oxides and their influence on the properties of the ensemble.

Abstract: Titanium Dioxide film will be deposited on a glass slide substrate by spin coating technique which is the frequently used technique because of its easy operation and cheap due to the sol gel preparation. The deposited films were then characterized by cross section technique using Field Emission Scanning Electron Microscopy (FESEM) to investigate the thickness based on the number of coatings. Then by the same FESEM, the surface morphology was studied to see the grain size and the porosity of each film based on the number of coatings. AFM was used to see the uniformity of the thin film's surface. Then by using current voltage (IV) measurement, the electrical property of the film can be studied, from IV characterization the resistivity of the film will be calculated. In this investigation, it is found that by increasing the coating layer, the resistivity values were decreasing whereas the conductivity of the film is increasing since conductivity is the inverse of resistivity. The porosity of the film also increases with the coating layers.