Ionic conductivity, structural and thermal properties of Ca2+ doped Y2Ti2O7 pyrochlores for SOFC

Yttrium titanate Y2Ti2O7 is an important member of the pyrochlore family because it exhibits various properties which make it suitable for potential applications in different fields. In the present study, influence of doping of CaO (0.1 ≤ x ≤ 0.4) for Y2Ti2O7 system was investigated. The lattice parameter, electrical conductivity, X-ray analysis, Fourier Transform-Infrared Spectroscopy (FTIR) and thermal expansion coefficient (TEC) were obtained in-order to study its suitability in the field of Solid Oxide Fuel Cells. The results show that doping of Ca ion on the Y-site plays an important role to determine electrical, thermal as well as structural properties. Moreover, it was observed that sintering up to 1550 °C for 12 h results in the formation of single Y2Ti2O7 cubic pyrochlore phase. In addition to this, structural studies including both SEM/EDX analysis were done to determine grain size as well as porosity in the system.