Electrical Properties of Ce_0.8Dy_0.175Ca_0.025O_2-δ

The present paper is focused on the structure, microstructure, and electrical properties of Ca (calcium)- and Dy (dysprosium)-doped ceria electrolyte materials. The CaDDC (Ce_0.8Dy_0.175Ca_0.025O_2-δ) sample was prepared through a modified sol–gel low-temperature process using sucrose and pectin. Rietveld analysis of powder x-ray diffraction (XRD) patterns confirms the cubic structure with a single phase. The Raman spectroscopy studies confirm the improved oxygen vacancies for the sample CaDDC over pure ceria. The scanning electron microscopy (SEM) images showed the highly dense surface. Energy-dispersive spectroscopy (EDS) confirms the sample chemical composition. Impedance spectroscopic studies were carried out to analyze the electrical properties. Migration energy (E_m) and association energy (E_asso.) were calculated from the dielectric relaxation process for oxide ion migration. Relaxation peaks were observed in tangent loss due to the presence of defect pairs. Modulus analysis showed a single relaxation peak, which indicates the reorientation of defect associates. The Ce_0.8Dy_0.175Ca_0.025O_2-δ sample exhibits improved conductivity of 1.23 × 10^–2 S/cm at 600°C with an activation energy of 0.89 eV.