Gallium-doped lanthanum germanates as electrolyte material of solid oxide fuel cells

Abstract

In this study, the effects of various amounts of Ga 3+ dopants on the densification, phase structure, microstructure and electrical conductivity of La 9.5 Ge 6.0 O 26.25 ceramics are examined. The incorporation of Ga 3+ ions into the La 9.5 Ge 6.0 O 26.25 lattices leads to the retardation of the densification and an increase in the triclinic structure, caused by the evaporation of GeO 2 and the largeness of the size difference between the Ga 3+ ions and Ge 4+ ions. Of the compositions studied, the La 9.5 Ge 5.7 Ga 0.3 O 26.1 ceramic sintered at 1450°C shows an electrical conductivity of 4.02 © 10 ¹2 Scm ¹1 at 800°C, which is higher than that of an 8YSZ ceramic. The