Synthesis and electrophysical properties of (1 − x

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• 作者：E.Yu. Pikalova ; V.I. Maragou ; A.K. Demin ; A.A. Murashkina ; P.E. Tsiakaras
• 关键词：Elecrophysical properties of CGO ; Doped С ; е ; Ae ; ₂-materials ; TiO₂ additives
• 刊名：Solid State Ionics
• 出版年：2008
• 出版时间：30 September 2008
• 年：2008
• 卷：179
• 期：27-32
• 页码：1557-1561
• 全文大小：481 K

文摘

In the present work the electrical properties of (1 − x)Ce_0.8Gd_0.2O_2 − 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 Ce_0.8Gd_0.2O_2 − 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 Ce_0.8Gd_0.2O_2 − 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 Ce_0.8Gd_0.2O_2 − 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 Ce_0.8Gd_0.2O_2 − 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 % .