Reducing the Gadolinium Dopant Content by Partial Substitution with Yttrium in a Ce0.9Gd0.1O1.95-based Oxide-Ion Conductor

• Main Authors: Mori, Masashi, Sumi, Hirofumi, Suda, Eisaku
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/07801.0377ecst

Ce0.9Gd0.1O1.95 is widely used as an oxide-ion conductor in solid-state electrochemical cells, but the Gd dopant is costly. We aimed to reduce the Gd content in this type of conductor by carrying out tests on the Ce0.9Gd0.1-xYxO1.95 system. The sintering characteristics of Ce0.9Y0.1O1.95 were better than those of Ce0.9Gd0.1O1.95. The electrical conductivity of Ce0.9Y0.1O1.95 at 600°C was 0.0184 S/cm, which was approximately 71% of that of Ce0.9Gd0.1O1.95. Each co-doped Ce0.9Gd0.1-xYxO1.95 ceria sample investigated was found to form a single fluorite phase, and they all showed similar sintering behavior. The conductivity of Ce0.9Gd0.075Y0.025O1.95 at 600°C was 0.0259 S/cm, the same as that of Ce0.9Gd0.1O1.95. After annealing at 600°C, Ce0.9Gd0.075Y0.025O1.95 showed lower rates of decrease in conductivity, compared with those of Ce0.9Gd0.1O1.95. These results suggested that it is possible to reduce the gadolinium content in Ce0.9Gd0.1O1.95 by 25% through substitution with yttrium.