Surface and Optical Properties of Gd-Doped ZrO2 Nano Films

Abstract

Nanosized coatings of ZrO2 were deposited on silicon substrates using sol-gel and spin coating techniques. The precursor solutions were prepared from ZrOCl2.8H2O with the addition of different percentage (0.5–5%) of rare earth Gd3+ ions as dopant. The thin films were homogeneous, with average thickness of 115 nm and refractive index (n) of 1.83. The X-ray diffraction analysis (XRD) revealed the presence of a varying mixture of monoclinic and tetragonal ZrO2 polycrystalline phases, depending on the dopant, all of which with nanosized crystallites. Scanning electron microscopy (SEM) as well as atomic force microscopy (AFM) methods were deployed to investigate the surface morphology and roughness of the thin films, respectively. They revealed a smooth, well uniform and crack-free surface with average roughness of 0.8 nm. It was established that the dopant concentration affects the photoluminescence (PL) properties of the samples. The undoped films exhibited broad violet-blue PL emission, while the addition of Gd3+ ions resulted in new narrow bands in both UV-B and visible light regions, characteristic of the rare earth metal. The intensive emission located at 313 nm can find useful application in medical lamps for treatment of different skin conditions.

Corrosion-Resistive ZrO2 Barrier Films on Selected Zn-Based Alloys

“…ZrO 2 also exhibits high chemical stability, wear resistance and hardness, which are the prerequisites for effective corrosion protection [1,2]. Zirconia-based coatings can be prepared using various physical and chemical techniques, such as physical vapor deposition (PVD) [3], magnetron sputtering [4], chemical vapor deposition (CVD) [5], plasma spray [6], hydrothermal process [7] and sol-gel process [8].…”