Microstructural design of sensor materials using the core-shell concept

An yttria stabilised zirconia which exhibits a core-shell microstructure wa s investigated as a method to produce a zirconia with high ionic conductivi ty and improved thermal shock resistance. Zirconia grains consist of an out er shell of tetragonal zirconia with an inner care of monoclinic phase zirc onia. Impedance spectroscopy was used to identify the effect of processing conditions on the grain boundary and grain interior ionic conductivity. At optimised processing conditions the grain boundary conductivity was found t o be significantly higher than conventional yttria stabilised zirconia. A s mall improvement in thermal shock resistance of the material was also obser ved. (C) 1998 Elsevier Science Limited All rights reserved.