Densification, morphological and transport properties of functional La1–xBaxYbO3–δ ceramic materials.

• The La 1–x Ba x YbO 3– δ (LBY) materials were successfully synthesized. • Ba-doping results in a deterioration of sintering behaviour of LBY. • Transport properties of LBY were studied by AC and DC conductivity measurements. • Bulk conductivity changes more sharply than the grain boundary one with x variation. • La 0.97 Ba 0.03 YbO 3– δ exhibits the highest conductivity values. The effective operation of protonic ceramic electrochemical cells requires the design of electrolytes having not only high ionic conductivity, but also excellent stability with respect to carbonisation. In the present work, the La-based oxides (La 1–x Ba x YbO 3– δ, 0.03 ≤ x ≤ 0.10) are proposed as a possible alternative to the convenient Ba(Ce,Zr)O 3 -based electrolytes due to their high chemical stability. It was discovered that Ba-doping results in a deterioration of sintering behaviour; as a result, the relative density decreases and open porosity appears (for x = 0.10). A thorough analysis of transport properties by means of AC and DC measurement techniques enables a selection of the La 0.97 Ba 0.03 YbO 3– δ sample, which demonstrates the highest conductivity compared with those samples where x = 0.5 and 0.10. Due to its excellent densification behaviour, stability and ionic conductivity, La 0.97 Ba 0.03 YbO 3– δ can be considered as a promising proton-conducting electrolyte in the La-based family. [ABSTRACT FROM AUTHOR]