The electrical, thermal and structural properties of CeO_2/(Li_(0.52)Na_(0.48))_2CO_3 coexisting system are investigated by AC impedance, differential thermal analysis and polarized Raman scattering spectroscopy. The system shows a dependence of the electrical conductivity upon the temperature. The transition point varies with the apparent average thickness of the liquid phase, while the activation energy, ΔE_a, remains constant at any distance from the solid phase. The symmetric stretching mode of the polarized Raman spectra shows that carbonate ion maintains its D_(3h) symmetry in the presence of ceria. A constant value of the depolarization ratio of the v_1(A'1) mode with regard to the apparent average thickness confirms that the symmetry of carbonate ions in the molten state is not altered by the presence of ceria powder. These findings contribute to the understanding of the properties of ceria-based carbonate electrolyte for intermediate temperature fuel cells.
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