Nanostructured samaria-doped ceria with improved grain-boundary conductivity via SPS and post-SPS annealing

Abstract

The 90 nm grained Ce_0,8Sm_0,2O_1,9 (SDC) ceramic with relative density of 97% was consolidated via SPS at 1050—1150 °C. The total conductivity values of 0,0079—0,0115 S/cm at 600 °C were obtained. A new approach to improve the grain-boundary conductivity of SDC nano-ceramic has been suggested. The applying of post-SPS low-temperature annealing enabled to decrease the grain-boundary resistance for 1/3, just slight increase in average grain size which avoid increasing of bulk resistance and as a result increase the total conductivity for almost 50%. In addition the SPS followed with post-SPS annealing was shown to be very useful in precise manipulation by the grain size/grain boundary quality/ceramic density, which in turn allow significant property enhancement of nanostructured SDC solid electrolytes.