Oxygen-conducting Composites Based on Me2(WO4)3 (Me = Sm, Al)

Abstract

Composites Sm 2 (WO 4 ) 3 -WO 3 and Al 2 (WO 4 ) 3 -WO 3 were prepared by the solid-state method and a systematic study of their electrotransport properties has been carried out. A sharp increase in the oxygen-ion conductivity is observed in composites Sm 2 (WO 4 ) 3 –WO 3 at small WO 3 values (about 10 mol.%). This effect is probably caused by formation of the non-autonomous interface phase covering grain boundaries of Sm 2 (WO 4 ) 3 . These composite O 2− – electrolytes are perspective materials for high temperature fuel cells. Тhe composite effect is absent in the Al 2 (WO 4 ) 3 –WO 3 system. This is probably due to the negative thermal expansion coefficient of Al 2 (WO 4 ) 3 , which prevents the formation of a continuous high-conducting microphase film.