Synthesis and Conductivity Measurement of Lanthanum Zirconate Doped with Rare Earth Dopants

In this work, La2Zr2O7 with a pyrochlore structure was doped with Sc, Y, Nd, Sm and Gd into its Zr-site to investigate the dependence of conduction behavior on the dopant. A systematic study was also performed to study the relationship between Y content and the proton conductivity. The results revealed that La2Zr2O7 doped with Y had higher conductivity, compared with those doped with Sc, Nd, Sm and Gd. Among the samples doped with various content of Y, La-2(Zr0.9Y0.1)(2)O7-delta was identified to have a single pyrochlore phase, and exhibited the highest bulk conductivity of 3.68 x 10(-4) Scm(-1) at 600 degrees C in wet H-2. But such value is still not enough for the application as an electrolyte in fuel cells. Poor capability for water incorporation is one of the reasons restricting a further increase of the proton conductivity. (c) 2014 The Electrochemical Society. All rights reserved.