Dense Oxide Ion Conducting Apatites Prepared by Spark Plasma Sintering

作者：Orera A; Slater P R^*

来源：Proceedings of the National Academy of Sciences India Section A-Physical Sciences, 2012, 82(1): 43-48.

DOI：10.1007/s40010-012-0004-1

• Apatite
• Spark plasma sintering
• Ionic conductivity
• Solid oxide fuel cells

In this paper we present a study into the preparation of dense La8Y2Ge6O27 apatite electrolytes through both conventional and spark plasma sintering (SPS). For the SPS pellets, the effect of the starting precursor was also examined to include precursors prepared via both standard solid state and a new sol gel route. The results show that similar bulk conductivities (approximate to 1.5 x 10(-3) Scm(-1) at 550 degrees C) were found irrespective of the sintering method/precursor, although the grain boundary conductivity decreased with increasing sintering temperature, being hence lowest for the sample prepared by conventional sintering. A Ga substituted sample (La8Y2Ge5GaO26.5) was also prepared and sintered using spark plasma sintering. This showed similar conductivities to the undoped phase in agreement with prior results on conventionally sintered samples. In addition dense pellets of the series La9SrSi6-xGexO26.5 (x = 0, 3, 6) have been prepared by spark plasma sintering to study the effect of Si/Ge on the sintering and conductivity. Similar bulk conductivities were obtained for all samples, with the highest grain boundary (and hence total) conductivity observed for the pure germanate (x = 6).

• 出版日期2012-3