Application of DTA/DSC and dilatometry for optimization of Ba–Ce–Y–P–Si–O glass phase for composite protonic conductors based on BaCe0.9Y0.1O3−δ

The aim of this work was to determine the influence of chemical composition on thermal and electrical properties of selected glass from the BaO–CeO2–Y2O3–P2O5–SiO2 system. Properties of the investigated glasses were optimized in terms of glass-BaCe0.9Y0.1O3 composite protonic conductor preparation. Three types of glasses with different P2O5/SiO2 ratio were prepared and investigated. The DSC and XRD measurements indicated limited tendency to crystallization of obtained glasses up to T = 1023 K. The dilatometry measurements led to determination of the thermal expansion coefficients (TEC) and the softening point. It was found that obtained glasses soften in temperature range of 903–923 K, depending on the composition which is advantageous from the viewpoint of further preparation and formation of the composite material. The Electrochemical Impedance Spectroscopy measurements done as a function of temperature and gas atmosphere allowed to determine the activation energy of the electrical conductivity. Observed fluctuations of the activation energy with gas atmosphere suggest the possible role of the protonic defects in total conductivity. Based on the obtained results it can be stated that proposed glass system may be considered as the modifying phase for improvement of BaCe0.9Y0.1O3-based materials.