A. A. Solovyev

Bias-assisted magnetron sputtering of yttria-stabilised zirconia thin films

Cubic yttria-stabilized zirconia (YSZ) thin films were deposited by reactive magnetron sputtering on NiO-YSZ fuel cell anodes under different conditions. The influence of substrate bias voltage, temperature and porosity on texture and morphology of the deposited films were investigated. Comparing film morphology of YSZ grown on NiO-YSZ anodes, it was found that films deposited on a substrate with a large porosity were columnar and contained voids regardless of the deposition parameters. It was shown that only using of anode support with very high surface quality, substrate heating up to 500 °C and pulsed substrate bias (about -30 V MF) during film deposition is necessary for deposition of non-columnar thin films without voids and cracks that may be suitable for SOFC application.

Properties of low-emission coatings based on Ag and Cu deposited on polymer film by magnetron sputtering

Results of experiments on the deposition of multilayer low-emission coatings with “oxide-metaloxide” structure on polyethylene terephthalate film by magnetron sputtering are presented. The purpose of this work was to find the composition of coatings which would have high moisture resistance and the possibility to operate outside sealed glass units. For this purpose, coatings with TiO2/ZnO:Ga/Ag/ZnO:Ga/TiO2 and TiO2/Cu/TiO2 structures were proposed and their optical and electrical characteristics were investigated. The optimum thickness of coating layers which provides a good ratio of coating transparency in the visible range with reflection in infrared spectral region was obtained. It was shown that low-emission coatings based on a Ag layer have a higher transparency (82%) and reflection in the infrared region (93%) than coatings based on a Cu layer, for which these characteristics are 60% and 84%, respectively.

Performance Characteristics of Solid Oxide Fuel Cells with YSZ/CGO Electrolyte

This paper presents the results of performance evaluation of anode-supported solid oxide fuel cells (SOFC) with magnetron sputtered YSZ/CGO bilayer electrolyte, and composite LSCF-CGO cathode. Deposition of the YSZ/CGO electrolyte with the thickness of up to 14 microns was performed on the commercial anode substrates with dimensions of 5×5 cm2. The LSCF-CGO cathode of the fuel cells was formed by the screen-printing method. The microstructure of the YSZ/CGO bilayer electrolyte and LSCF-CGO cathode was studied by scanning electron microscopy. Comparison of the fuel cells performance with different thicknesses of the YSZ and CGO layers was carried out by measuring current-voltage and power characteristics, and also by testing the long-term stability of cell power at the temperature of 750 °C and voltage of 0.7 V.

The Deposition of Silicon-Carbon Coatings in Plasma Based Nonself-Sustained Arc Discharge with Heated Cathode

Silicon-carbon coatings on silicon substrates were deposited in plasma based nonself-sustained arc discharge with heated cathode by plasma polymerization of silicon organic agent such as polyphenyl methylsiloxane (PPhMS). Silicon-carbon coatings were deposited at PPhMS flow rate of 0.012 ml/min, argon pressure of 0-0.1 Pa, discharge current of 5-8 A, discharge voltage of 130-150 V, and filament current of 68 A. Bipolar pulsed bias voltage was supplied on the substrate during coating deposition. Surface morphology, hardness and elastic modulus of silicon-carbon films were investigated after the deposition. The film surface is very smooth with root-mean-square roughness of 0.579 nm. Maximum hardness of coatings was 11 GPa, and maximum elastic modulus was 142 GPa.

Deposition of a Thin-Film CGO Electrolyte for Solid Oxide Fuel Cells

Reducing the operating temperature of solid oxide fuel cells (SOFCs) from 800-1000°C is one of the main SOFC research goals. It can be achieved by lowering the thickness of an electrolyte (ZrO2:Y2O3 (YSZ) is widely used as electrolyte material). On the other hand the problem can be solved by using of another electrolyte material with high ionic conductivity at intermediate temperatures. Therefore the present study deals with magnetron sputtering of ceria gadolinium oxide (CGO), which has a higher conductivity compared to YSZ. The microstructure of CGO layers deposited on porous NiO/YSZ substrates by reactive magnetron sputtering of Ce:Gd cathode is investigated. Current voltage characteristics (CVC) of a fuel cell with NiO/YSZ anode, CGO electrolyte and LSCF/CGO cathode were obtained. It was shown that the power density of a fuel cell with CGO electrolyte weakly depends on the operating temperature in the range of 650-750°C in contradistinction to YSZ electrolyte, and is about 600-650 mW/cm2.