Microstructural interpretation of conductivity and dielectric response of Ce0.9Eu0.1O1.95 oxygen ion conductors

This work focuses on the structure property co-relation study of Eu3+-doped ceria nanomaterials prepared through citrate auto-ignition process and sintered at three different temperatures. The microstructure and dielectric properties were found to be affected by the sintering temperature. The particle size was found to play a major role to the migration of charge carriers in the samples. The dielectric constant has been found to control the formation of dopant-vacancy interaction though columbic interaction in defect pair (Eu'(Ce) - V-o center dot center dot)center dot and neutral trimers (Eu'(Ce) - V-o center dot center dot - Eu'(Ce)). The sample sintered at 800 degrees C shows the lowest value of lattice parameter due to the highest value of dopant-vacancy interaction. The migration energy for oxygen vacancy conduction was found to increase with particle size that reduces the ionic conductivity values. The rate of hopping was found to decrease due to blocking of charge-carrier diffusion due to the growth of particle.