Electronic conductivity of Ni-doped yttria-stabilized zirconia

The electronic conductivity of (NiO)0.01[(Y2O3)0.08(ZrO2)0.92]0.99 was measured with a modified ion blocking method at 1273 K in the oxygen partial pressure (p(O2)) range of 10− 3–10− 17 MPa. At p(O2) > 10− 6 and < 10− 14 MPa, the electronic conductivity was proportional to the 1/4 and − 1/4 power of p(O2) due to hole and electron conduction, respectively. The electron conductivity was obviously smaller for Ni-doped YSZ than for YSZ by a factor of 2.0 at p(O2) range of 10− 14–10− 17 MPa. The measured electronic conductivity of Ni-doped YSZ was used to calculate the oxygen potential distribution in the electrolyte under the ion blocking condition. The lower oxygen potential region in the electrolyte was in excellent agreement with the darkly colored region found in the Ni-doped YSZ electrolyte after the electronic conductivity measurements.