Intermixing of metal oxide/Ag/metal oxide nanoscale multilayers prepared by rf reactive magnetron sputtering

This study mainly aims to evaluate the intermixing between layers during the deposition of dielectric/metal/dielectric nanoscale multilayer coatings. TiO(2) and WO(3) films as dielectric materials are developed using radio frequency reactive magnetron sputtering on unheated soda lime glass substrates. Ag films are grown using radio frequency argon sputtering. Auger electron spectroscopy and ultraviolet-visible-near infrared spectrometry are employed to estimate the degree of layer intermixing in TiO(2)/Ag, WO(3)/Ag, TiO(2)/Ag/TiO(2) and WO(3)/Ag/WO(3) films. The morphological properties are also investigated under a field emission scanning electron microscope and an atomic force microscope. The transmittance curves for bilayer films exhibited heat mirror effects significantly. However, multilayer films showed a little amount of heat mirror effects. Auger electron spectroscopy depth profiles confirmed a minor diffusion of Ag at the TiO(2)/Ag interface. However, significant interactions of WO(3) with Ag were observed for the WO(3)/Ag film. Besides, severe intermixing and oxidation of Ag films were observed for the multilayer films

Structural and mechanical properties of nanostructured TiO2 thin films deposited by RF sputtering

This study mainly aims to evaluate the effects of substrate temperatures on the mechanical properties of TiO2 thin films deposited on glass substrates by radio-frequency (RF) magnetron sputtering. All titania films possess anatase structure having a nodular morphology. AES results reveal that Si and Na ions from glass diffuse into TiO2 films at higher substrate temperatures Micro-scratch and wear tests were conducted to evaluate their mechanical and tribological properties The adhesion critical loads of TiO2 films deposited at room temperature, 200 and 300 degrees C are found to be 1.51, 1.54 and 1.08 N. respectively Scratch hardness also Increases from 11.5 to 13 6 GPa with increasing temperature The wear track width decreases with substrate temperature indicating an improved wear resistance at higher temperatures (C) 2010 Elsevier B.V. All rights reserved

Overall thermal transfer value of residential buildings in Malaysia

This study presents the Overall Thermal Transfer Value (OTTV) and the energy consumption of room air conditioners of the residential buildings in Malaysia. A survey has been conducted to investigate the OTTV and the energy consumption of room air conditioners of the residential buildings in Malaysia. OTTV calculation, energy consumption and effect of the building parameters on energy consumption have been investigated. It is found that OTTV of the residential buildings in Malaysia varied from 35 to 65 W m -2 with a mean value of 41.7 W m -2. The sensitivities of several parameters such as window to wall ratio (WWR), Shading Coefficient (SC), U-value for wall (U w) and solar absorption (α) are provided to design and optimize the thermal performance of residential buildings. It is found that U and α influence more on OTTV compared to other parameters. The analysis shows that about 14, 10 and 5 of residential building air conditioners have annual electricity consumption in the ranges 500 to 1000 kWh, 1000 to 2000 kWh and 7500 to 10000 kWh, respectively. The maximum, minimum and average annual electricity consumption of the air conditioner of residential buildings is 22055.5, 136.1 and 3708.8 kWh, respectively. © 2009 Asian Network for Scientific Infor

Effects of annealing treatment on optical properties of anatase TiO2 thin films

In this investigation, anatase TiO2 thin films were grown by radio frequency magnetron sputtering on glass substrates at a high sputtering pressure and room temperature. The anatase films were then annealed at 300-600 °C in air for a period of 1 hour. To examine the structure and morphology of the films, X-ray diffraction (XRD) and atomic force microscopy (AFM) methods were used respectively. From X-ray diffraction patterns of the TiO 2 films, it was found that the as-deposited film showed some differences compared with the annealed films and the intensities of the peaks of the crystalline phase increased with the increase of annealing temperature. From AFM images, the distinct variations in the morphology of the thin films were also observed. The optical constants were characterized using the transmission spectra of the films obtained by UV-VIS-IR spectrophotometer. Besides, optical thickness of the film deposited at room temperature was calculate

Effects of annealing treatment on optical properties of anatase TiO 2 thin films

In this investigation, anatase TiO 2 thin films were grown by radio frequency magnetron sputtering on glass substrates at a high sputtering pressure and room temperature. The anatase films were then annealed at 300-600 °C in air for a period of 1 hour. To examine the structure and morphology of the films, X-ray diffraction (XRD) and atomic force microscopy (AFM) methods were used respectively. From X-ray diffraction patterns of the TiO 2 films, it was found that the as-deposited film showed some differences compared with the annealed films and the intensities of the peaks of the crystalline phase increased with the increase of annealing temperature. From AFM images, the distinct variations in the morphology of the thin films were also observed. The optical constants were characterized using the transmission spectra of the films obtained by UV-VIS-IR spectrophotometer. Besides, optical thickness of the film deposited at room temperature was calculated and cross-checked by taking a cross-sectional image through SEM. The optical band gaps were evaluated through Tauc model. It was observed that TiO 2 films produced at room temperatures exhibited high visible transmittance and transmittance decreased slightly with the increase of annealing temperatures. The films were found to be crystalline having anatase phase. The refractive index of the films was found from 2.31-2.35 in the visible range. The extinction coefficient was nearly zero in the visible range and was found to increase with annealing temperature. The allowed indirect optical band gap of the films was estimated to be in the range from 3.39 to 3.42 eV which showed a small variation. The allowed direct band gap was found to increase from 3.67 to 3.72 eV. The porosity was also found to decrease at a higher annealing temperature making the film compact and dense

Influence of substrate and annealing temperatures on optical properties of RF-sputtered TiO2 thin films

TiO2 thin films were deposited on unheated and heated glass substrates at an elevated sputtering pressure of 3 Pa by radio frequency (RF) reactive magnetron sputtering. TiO2 films deposited at room temperature were annealed in air for 1 h at various temperatures ranging from 300 to 600 °C. The structural and optical properties of the thin films were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet–visible–near infrared (UV–VIS–NIR) spectrophotometry. XRD results show that as-grown and post-annealed TiO2 films have anatase crystal structure. Higher substrate and annealing temperatures result in a slight increase of crystallinity. TiO2 films deposited at different substrate temperatures exhibit high visible transmittance and the transmittance decreases slightly with an increase in annealing temperature. The refractive indices (at λ = 550 nm) of the as-deposited and annealed films are found to be in the range of 2.31–2.37 and 2.31–2.35, respectively. Extinction coefficient decreases slightly with increasing substrate and annealing temperatures. The indirect and direct optical band gap of the as-grown films increases from 3.39 to 3.42 eV and 3.68 to 3.70 eV, respectively, with the increase of substrate temperatures. Annealed TiO2 films also exhibit an increase in the values of indirect and direct optical band gap

Structural, optical and morphological properties of TiO 2/Ag/ TiO 2 multilayer films

In this investigation, TiO 2/Ag/TiO 2 multilayer-films were deposited on microscope glass slides with varying individual layer thicknesses by radio-frequency reactive magnetron sputtering. Prior to multilayer development, single layers of Ag and TiO 2 were deposited and characterized. All the films were prepared at a moderately high pressure at room temperature. It was found that single layer of TiO 2 showed anatase polycrystalline structure. It also exhibited high visible transmittance of above 80 and higher refractive index of 2.31 at a wavelength of 550 nm. The indirect optical band gap of the TiO 2 films was estimated as 3.39 eV. The Ag single layer films were found to be crystalline with a very high reflectance for IR (Infra-red) light. Finally, the multilayers have been deposited and characterized by X-ray diffraction, UV-visible-IR spectrophotometry, scanning electron microscopy and profilometry

Structural, optical and morphological properties of TiO∕ Ag∕ TiO multilayer films

In this investigation, TiO2/Ag/TiO2 multilayer‐films were deposited on microscope glass slides with varying individual layer thicknesses by radio‐frequency reactive magnetron sputtering. Prior to multilayer development, single layers of Ag and TiO2 were deposited and characterized. All the films were prepared at a moderately high pressure at room temperature. It was found that single layer of TiO2 showed anatase polycrystalline structure. It also exhibited high visible transmittance of above 80% and higher refractive index of 2.31 at a wavelength of 550 nm. The indirect optical band gap of the TiO2 films was estimated as 3.39 eV. The Ag single layer films were found to be crystalline with a very high reflectance for IR (Infra‐red) light. Finally, the multilayers have been deposited and characterized by X‐ray diffraction, UV‐visible‐IR spectrophotometry, scanning electron microscopy and profilometry