GRAIN BOUNDARY CONDUCTIVITY ENHANCEMENT IN CERIA-GADOLINIA SOLID SOLUTIONS

摘要

The electrical conductivity of ceria-gadolinia (CGO) with small additions of calcium have been studied in an attempt to improve the grain boundary conductivity. The results show that a large increase in the grain boundary conductivity is obtained, which is attributed to a higher ionic conductivity calcium phase at the grain boundary. The best total conductivity was found for a 9mol% Gd-lmol% Ca sample. D.C. Conductivity results taken at selected pO_2 at 750℃, showed the conductivity to be ionic at high pO_2's and electronic at pO_2's lower than 10~(-15)atm.