Electrical conductivity of polycrystalline 3Y 2O 3·WO 3 at high temperatures

Abstract

The electrical conductivity of polycrystalline Y 6WO 12 (3Y 2O 3·WO 3) and of polycrystalline Y 6WO 12 doped with alkaline earth oxides or ZrO 2 were measured over the temperature range from 800 to 1400°C under oxygen partial pressures of 10 −5 to 10 0 atmospheres. Y 6WO 12 showed a p-type conductivity at higher oxygen pressures and an n-type conductivity at lower oxygen pressures. Additions of alkaline earth oxides increased the conductivity of Y 6WO 12 in the higher oxygen pressure region. The conductivity of alkaline earth oxides-doped Y 6WO 12 decreased monotonically with decreasing oxygen partial pressures and approached constant values at lower oxygen partial pressures. The ZrO 2 addition caused a decrease in the conductivity of Y 6WO 12 in the higher oxygen pressure region. The variations of the conductivity with oxygen pressure are discussed assuming various defects models.