Low temperature processing of dense samarium-doped CeO₂ ceramics: sintering and intermediate temperature ionic conductivity

Abstract

Samarium-doped Ceria powders for solid electrolyte ceramics were synthesized by a combustion process. Cerium nitrate and samarium nitrate were used as the starting materials, and glycine was used as fuel. Decomposition of unburned nitrogen and carbon residues was investigated by simultaneous thermogravimetry analysis and differential thermal analysis experiments. The X-ray diffraction results showed that the single-phase fluorite structure forms at a relatively low calcination temperature of 800 °C. X-rays patterns of the SDC powders revealed that the crystallite size of the powders increases with increasing calcination temperature. The sintering behavior results showed that more than 96% of the relative density is obtained for powders sintered at 1,100 °C for 8 h. The alternating current impedance spectroscopy results showed that the SDC15 sample sintered at 1,100 °C has ionic conductivity of 0.015 Scm⁻¹at 650 °C in air. The present work results have indicated that glycine–nitrate route is a relatively low-temperature preparation technique to synthesize SDC powders with a high sinterability and a good ionic conductivity.