Temperature independent resistive oxygen sensors using solid electrolyte zirconia as a new temperature compensating material

We have proposed that an oxide-ion conductor is a new candidate of temperature compensating material (TCM). The thick films of zirconium oxide doped with Y, Ca, or Nd of various concentrations and Zr-doped ceria were fabricated and temperature dependence of their resistance was investigated in temperature range from 773 to 973 K. Activation energy of resistance for the thick film of Ce0.90Zr0.10O2 and Ce0.95Zr0.05O2 as oxygen partial pressure measurement materials (OMM) was 1.52 and 1.43 eV in temperature range of 773–973 K. Activation energy of resistance for the thick film of solid electrolyte zirconia, that is, Zr1−xMxO2−δ (M: Nd, Ca, Y; x: 0.1–0.4) was in the range of 1.13–1.35 eV, and the Zr0.7Y0.3O2−δ thick film made from the powder obtained by new precipitation method showed the highest value of activation energy that was 1.35 eV. Therefore, the resistive oxygen sensors using Ce0.95Zr0.05O2 thick film (CeZr5) as OMM and Zr0.70Y0.30O2−δ thick film (ZrY30P) as TCM were fabricated and their sensor properties were investigated. The output of the sensor was dependent on oxygen partial pressure and approximately independent from temperature in high oxygen partial pressure range. Also in low oxygen partial pressure range, the temperature dependence of the sensor output was also small.