Influence of La3+, Sm3+and Dy3+ dopants on ceria solid electrolytes for IT–SOFCs

The La3+, Sm3+ and Dy3+ triple doped ceria Ce1–x–y–zLaxSmyDyzO2-δ (x/y/z = 0.02, 0.04, 0.06, 0.08, and 0.10) ceramics were prepared successfully. Prepared ceramics were sintered using conventional sintering at 1300 °C and relative density values found to above 95%. Phase identification, micro-structure, thermal, as well as electrical studies of prepared ceramics were investigated using Powder X–ray Diffraction, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Micro-Raman, Impedance as well as Thermal Expansion characterizations. From this investigation, the ceramics with single-phased cubic structure, uniformly-distributed grains, high-density in microstructure, presence of compositional elements, and relative oxygen vacancies were confirmed in the compositions. The high electrical conductivity (0.027 S/cm at 550 °C) and low activation energy (0.82 eV) as well as matched thermal expansion coefficient of Ce0.82La0.06Sm0.06Dy0.06O2-δ (CLSD6) makes its possibility in intermediate temperature – solid oxide fuel cell applications.