Influence of the oxygen partial pressure on the growth and optical properties of RF-sputtered anatase TiO2 thin films

Titanium dioxide (TiO2) films with thicknesses around 300 nm were deposited on glass substrates by reactive radio frequency (RF) magnetron sputtering at constant RF sputtering power (200 W), high sputtering pressure and room temperature. The effects of the oxygen presence on the growth and properties of the films were investigated using mixtures of Ar and O2 with different O2/(Ar + O2) ratios (from 0.0 to 0.3) during the sample deposition. The crystalline properties and surface morphology were characterized using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The optical properties were studied by ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy, and the refractive index and the thickness of the samples were obtained using the Swanepoel method. The obtained results indicate that all the TiO2 films grew with an anatase phase and with an improved crystallinity at O2/(Ar + O2) = 0.2. However, AFM studies show that the grain size and surface roughness decrease as the O2/(Ar + O2) ratio increases from 0.0 to 0.3. Moreover, a maximum refractive index was obtained for the sample prepared at O2/(Ar + O2) = 0.2

Microstructure and optical properties of cobalt–carbon nanocomposites prepared by RF-sputtering

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Evaluating the Topological Surface Properties of Cu/Cr Thin Films Using 3D Atomic Force Microscopy Topographical Maps

In the present work, Cu/Cr thin films were deposited on substrates of a different nature (Si, Glass, Bk7, and ITO) through a thermal evaporation deposition method. Non-contact atomic force microscopy (AFM) was used to obtain 3D AFM topographical maps of the surface for the Cu/Cr samples. Various analyses were carried out to obtain crucial parameters for the characterization of the surface features. In particular, Minkowski functionals (including the normalized Minkowski volume, the Minkowski boundary, and the Minkowski connectivity) and studies of the spatial microtexture by fractal and multifractal analyses were carried out. Different roughness parameters (including arithmetical mean height, root mean square height, skewness, kurtosis, fractal dimension, Hurst coefficient, topographical entropy, and fractal lacunarity) were quantified in these analyses for the comparison of the surface morphology of the different samples. All the samples displayed non-Gaussian randomly rough surfaces, indicating the presence of multifractal features