Electronic conductivity of 20 mol % YO_1.5 doped CeO₂

The temperature and the oxygen partial pressure dependencies of hole and electron conductivity of 20 mol % YO_1.5 doped CeO₂ (20 YDC) were measured by a dc polarization method using a Hebb-Wagner ion-blocking cell from 973 to 1273 K at oxygen partial pressures log p_O2[MPa] = -9 to -1. The electron conductivity is proportional to p_O2^-1/4 in the lower p_O2 region. In the high oxygen potential region, a small polarization method was applied to avoid the failure of gas tightness at the ion blocking interface. This enabled the hole contribution, which is found to be proportional to p_O2^1/4 in the higher p_O2 region to be distinguished. The activation energy of electron conduction is 2.25 eV (at log p_O2 [MPa] = -7). The activation energy of hole conduction is 1.24 eV (at log p_O2 [MPa] = -1).