Investigation of Plasma-Sprayed Zirconia-Based Electrolytes

Kurzfassung

Solid oxide fuel cells (SOFC) operating in the temperature range between 800–1000 °C are devices converting directly chemical energy into electrical energy. The SOFC electrolyte layer typically consisting of yttria-stabilized zirconia (YSZ) was prepared using atmospheric plasma spraying technology. Plasma spraying is a cost-effective technique for the production of functional layers in SOFCs. Properties, such as microstructure, conductivity of YSZ electrolyte layers were investigated by Scanning electron microscopy (SEM), X-ray diffraction (XRD), 4-point dc method, and mercury intrusion porosimetry and Raman spectroscopy. Raman spectroscopy is a powerful tool for the investigation of structural features, for example, crystallinity, molecular orientation, and phase composition, especially of inorganic thin films. In this study we show that depending on the preparation conditions the crystal growth and the density of the plasma-sprayed thin films can be influenced significantly. Therefore Raman spectra as well as XRD and SEM pictures show subtle differences concerning the crystallinity of various samples