Donor and acceptor co-doped SrTiO3 materials have shown interesting features in their conductivity and reducibility. In this work, 10 mol% Na+ or K+ as acceptor dopants have been introduced into the A-site of donor-doped strontium titanate, SrTi0.8Nb0.2O3, and the doping impact on their properties has been studied. By doping with Na or K, the sinterability of SrTi0.8Nb0.2O3 in reducing atmospheres has been improved. Na0.1Sr0.9Ti0.8Nb0.2O3 and K0.1Sr0.9Ti0.8Nb0.2O3 show metallic conduction behavior after being sintered at 1400 °C in 5% H2/N2. Electrical conductivity reaches 1180 S cm−1 at 400 °C and 272 S cm−1 at 800 °C for K0.1Sr0.9Ti0.8Nb0.2O3, which is higher than that of Sr0.99Ti0.8Nb0.2O3 prepared under similar conditions, indicating the improved reducibility of acceptor doped SrTi0.8Nb0.2O3. Such improvement may be attributed to the improved oxide ionic conductivity and cation mobility at high temperatures. Reduced polarization resistance is also observed using Na0.1Sr0.9Ti0.8Nb0.2O3 and K0.1Sr0.9Ti0.8Nb0.2O3 as anodes on YSZ electrolytes, suggesting improved catalytic activity by Na/K-doping.
Published in Journal of Materials Chemistry A, Volume 1, Issue 35, 2013, pages 10546-10552.
©Journal of Materials Chemistry A 2013, Royal Society of Chemistry.
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This article was first published by the Royal Society of Chemistry and can be found at http://dx.doi.org/10.1039/C3TA11631J
Xiao, G., Nuansaeng, S., Zhang, L., Suthirakun, S., Heyden, A., zur Loye, H.-C., & Chen, F. (21 September 2013). Enhanced Reducibility and Conductivity of Na/K-Doped SrTi0.8Nb0.2O3. Journal of Materials Chemistry A, 1 (35), 10546 – 10552. http://dx.doi.org/10.1039/C3TA11631J