Influence of sintering methods on microstructure and ionic conductivity of La_1.95Sr_0.05Zr₂O_6.975 synthesized by co-precipitation

We present here the synthesis of Sr-doped lanthanum zirconate pyrochlores La_1.95Sr_0.05Zr₂O_6.975 with controlled grain sizes and we compare different methods of sintering. Pyrochlores are systems where it is hard to achieve high density without a significant coarsening of the sample microstructure. It is shown that the use of Spark Plasma Sintering (SPS) can produce high density ceramic samples while maintaining a nano-metric grain size, a key factor for enhancing electrical and mechanical properties. Furthermore, ionic conductivity is found higher in samples sintered using SPS than in those produced by hot pressing. (authors)