Patent ID: 9624133
Date: 2017-04-18
CPC Classifications: C04B,G01N

Claim:
1. A solid electrolyte, for use in gas sensors, made of zirconia grains and fine alumina grains so that the fine alumina grains are dispersed in the grain boundaries of the zirconia grains using yttria as stabilizer, wherein the solid electrolyte contains a range of 2 to 10 mol % of yttria per zirconia grains, and a range of 10 to 15 mass % of alumina grains in the entire solid electrolyte, and the solid electrolyte has a relative density of not less than 93%, the zirconia grains after firing have an average particle size Rz of not more than 2 μm, the alumina grains after firing have an average particle size of not more than 1 μm, the average particle size of the alumina grains after firing is smaller than that of the zirconia grains after firing, an average distance value A a standard deviation S the solid electrolyte satisfies a relationship of (S a sum of a grain boundary resistance and an internal grain resistance of the electrolyte having a size of 0.4 mm thickness and 16 mm diameter is within a range of 94.7 to 134.4 ohms at a temperature of 500° C., and the grain boundary resistance in a complex impedance of the solid electrolyte is within a range of 23.6 to 46.5 ohms.