Changes in structure and electrical conductivity of some rare-earth-doped ceria induced by strontium addition

• DOI: 10.1007/s11581-018-2792-z
• Publication Date: 2018-11-17T13:57:00Z
• Authors: Nicoleta Cioatera; Elena-Adriana Voinea; A. Dobritescu; Andreea Simionescu; C. I. Resceanu; C.-I. Spinu
• Keywords: Alkaline earth metal

In order to investigate the effect of strontium addition on the structure and ionic conductivity of rare-earth-doped ceria, powders with composition Ce0.85Dy0.15-xSrxO2-δ (x = 0, 0.05, 0.075) and Ce0.85Yb0.15-xSrxO2-δ (x = 0, 0.05, 0.075) are synthesized using a Pechini method. X-ray diffraction (XRD) and Raman spectroscopy analysis evidence the formation of single-phase solid solutions for all investigated powders and their corresponding sinters. An increase in grain size with strontium content is evidenced by scanning electron microscopy (SEM). Electrochemical impedance spectroscopy allows only the determination of total ionic conductivity of the investigated samples. The sample with stoichiometry Ce0.85Yb0.10Sr0.05O2-δ exhibits the highest ionic conductivity (8.6 × 10−4 S/cm at 500 °C) and the lowest activation energy of conduction (0.71 eV) among all investigated samples. The activation energy of conduction has a dominating effect on ionic conductivity for Ce–Yb system.