TY - JOUR

T1 - Synthesis and electrophysical properties of (1 - x)Ce0.8Gd0.2O2 - δ + xTiO2 (x = 0-0.06) solid-state solutions

AU - Pikalova, E. Yu

AU - Maragou, V. I.

AU - Demin, A. K.

AU - Murashkina, A. A.

AU - Tsiakaras, P. E.

PY - 2008/9/30

Y1 - 2008/9/30

N2 - In the present work the electrical properties of (1 - x)Ce0.8Gd0.2O2 - δ + xTiO2 (x = 0-0.06) synthesized by the standard ceramic technology were investigated, in a wide range of oxygen partial pressures (0.21-10- 20atm at 900 °C) and temperatures (600-900 °C), both in air and H2 + 3%H2O atmosphere. It was found, that only the introduction of above 1 mol% TiO2 decreases the sintering temperature of Ce0.8Gd0.2O2 - δ. The values of total electrical conductivity do not change significantly with the content of the sintering aid up to 3 mol%, while the activation energy of total conductivity in air decreases considerably with the introduction of TiO2 into Ce0.8Gd0.2O2 - δ from 87 to 67 kJ/mol; however, it is independent of x up to 0.03. The dependence of the total conductivity on the oxygen partial pressure is characterized by three regions. In the intermediate region (10- 10-10- 14) the conductivity behavior is described according to the oxygen vacancy model. The n-type conductivity region curve of Ce0.8Gd0.2O2 - δ is fitted to a -1/5 slope. The increase of TiO2 content leads to the slope increase at - 1/6, - 1/8 and - 1/9 for 1, 2 and 3 mol% TiO2, respectively, due to the trapping of electrons by Ti4+. 1 mol% doping increases the electrolytic region of Ce0.8Gd0.2O2 - δ from 10- 10 to 10- 13atm. Finally, the optimal content of TiO2 from the viewpoint of sintering and electrical properties was found to be 2 mol%.

AB - In the present work the electrical properties of (1 - x)Ce0.8Gd0.2O2 - δ + xTiO2 (x = 0-0.06) synthesized by the standard ceramic technology were investigated, in a wide range of oxygen partial pressures (0.21-10- 20atm at 900 °C) and temperatures (600-900 °C), both in air and H2 + 3%H2O atmosphere. It was found, that only the introduction of above 1 mol% TiO2 decreases the sintering temperature of Ce0.8Gd0.2O2 - δ. The values of total electrical conductivity do not change significantly with the content of the sintering aid up to 3 mol%, while the activation energy of total conductivity in air decreases considerably with the introduction of TiO2 into Ce0.8Gd0.2O2 - δ from 87 to 67 kJ/mol; however, it is independent of x up to 0.03. The dependence of the total conductivity on the oxygen partial pressure is characterized by three regions. In the intermediate region (10- 10-10- 14) the conductivity behavior is described according to the oxygen vacancy model. The n-type conductivity region curve of Ce0.8Gd0.2O2 - δ is fitted to a -1/5 slope. The increase of TiO2 content leads to the slope increase at - 1/6, - 1/8 and - 1/9 for 1, 2 and 3 mol% TiO2, respectively, due to the trapping of electrons by Ti4+. 1 mol% doping increases the electrolytic region of Ce0.8Gd0.2O2 - δ from 10- 10 to 10- 13atm. Finally, the optimal content of TiO2 from the viewpoint of sintering and electrical properties was found to be 2 mol%.

KW - Doped S{cyrillic}ye{cyrillic}O{cyrillic}-materials

KW - Elecrophysical properties of CGO

KW - TiO additives

UR - http://www.scopus.com/inward/record.url?scp=48349110554&partnerID=8YFLogxK

U2 - 10.1016/j.ssi.2007.12.086

DO - 10.1016/j.ssi.2007.12.086

M3 - Article

AN - SCOPUS:48349110554

VL - 179

SP - 1557

EP - 1561

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

IS - 27-32

ER -