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研究生:曾讓忠
研究生(外文):Tseng , Jang-Chumg
論文名稱:氧離子導體La2Mo2O9之高溫結構與導電率
論文名稱(外文):The High-Temperature Structure and Conductivity of Oxygen Ion Conductor La2Mo2O9
指導教授:蔡大翔
學位類別:碩士
校院名稱:國立臺灣科技大學
系所名稱:化學工程系
學門:工程學門
學類:化學工程學類
論文種類:學術論文
論文出版年:2002
畢業學年度:90
語文別:日文
論文頁數:96
中文關鍵詞:氧離子導體離子導電率鉬酸鑭氧化物結構分析
外文關鍵詞:oxygen ion conductorionic conductivityLa2Mo2O9structure analysis
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本論文研究氧離子導體La2Mo2O9的組成、離子導電率、結構之間的關聯。高溫相La2Mo2O9結構與β-SnWO4晶相結構極類似,空間群P213,與習知的氧離子導體結構不同。未摻雜之La2Mo2O9的800℃離子導電率約0.06 S cm-1,高於摻釔穩定氧化鋯,它在580℃附近有一階相轉變,高溫相導電率有急劇增加之現象。
我們利用固相反應法合成La2Mo2O9氧化物系列之粉體。未摻雜之驟冷La2Mo2O9粉末作X-Ray繞射分析,室溫下高溫相將逐漸轉變回低溫相,似乎其相變具有可逆性。利用熱分析儀(DTA)觀察樣品相轉變化,鑭離子位置摻雜10mol% 鉍、釓、釤、鎰之樣品,升溫至800℃過程中,沒有吸放熱事件,摻雜鈣、釹、鈰之樣品分別在577℃、570℃、566℃有明顯吸熱峰,未摻雜樣品於564℃有吸熱峰。
單軸冷壓成型之生胚在930℃燒結的相對理論密度最高,達95.9%;晶粒尺寸量測,摻雜10mol%之鉍、釓有增加燒結體晶粒尺寸之作用,而摻雜10mol%鈣對晶粒尺寸影響不大,且其相對密度較低,而摻雜10mol%釓似有粒界析出物。以同步輻射光源(SRRC)對試片作不同溫度下更高解析度之X-Ray繞射分析,實驗結果顯示,La2Mo2O9低溫相因氧缺陷序化而有超晶格之長距離結構,低溫相在(110)(2θ=17.4°)之前有較高溫相更複雜之繞射圖案,可觀察到七個微弱的繞射峰在相變後消失,初步認為這些峰屬於序化超晶格繞射。
交流阻抗分析,樣品300℃~800℃之離子導電率,發現摻雜10mol%之鉍、釓及鈣能提高La2Mo2O9之800℃下離子導電率,其中以摻雜10mol%鈣所得到之導電率值為最高,雖然其相對密度最低;由導電率對溫度倒數作圖(阿瑞尼士作圖),得到高低溫區之活化能值,未摻雜樣品,高溫相活化能8.9 kcal/mol,低溫相24.9 kcal/mol;10mol%鉍之樣品活化能29.8 kcal/mol;10mol%釓之樣品高溫相活化能8.6 kcal/mol,低溫相34.9 kcal/mol;10mol%鈣之樣品高溫相活化能11.9 kcal/mol,低溫相25.3 kcal/mol;低溫相之導電率溫度依存性通常較高溫相大。
This thesis investigates the relations among the compositions, ionic conductivities, and crystal structures of oxygen ion conductor La2Mo2O9. The high-temperature form of La2Mo2O9 has a structure similar to that of b-SnWO4 crystal, space group P213, which is different from the conventional oxygen ion conductors. The undoped La2Mo2O9 exhibits an ionic conductivity of 0.06 S cm-1 at 800°C, which is higher than that of yttrium-stabilized ZrO2. It shows a first-order phase transition near 580°C. Its ionic conductivity increases drastically after the phase change.
We synthesized the doped and undoped La2Mo2O9, using the solid state reaction method. X-ray diffraction patterns of quenched La2Mo2O9 powders indicate the high temperature form gradually converts to the low temperature form at room temperature. This fact seems to point out that the phase transition is reversible. The phase transition of La2Mo2O9 is inspected by the differential thermal analysis. La2Mo2O9 doped with 10 mol% Bi, Gd, Sm, or Yb (at La site) exhibits no thermal event up to 800°C, meanwhile, samples doped with 10 mole% Ca, Nd, Ce show marked endothermic peaks at 577, 570, 566°C, individually. The undoped La2Mo2O9 displays an endothermic peak at 564°C.
The sintered density of a powder compact, which is uniaxially cold-pressed, reaches 95.9% relative density at a temperature of 930°C. Measurements on the grain size of sintered bodies indicate that doping 10mol% Bi and Gd increases the grain size, and doping 10mol% Ca has an insignificant effect on the grain growth. Microstructure analysis of 10mol% Ca sample indicates grain boundary precipitates, and its density is lower than other doped samples. Much higher resolution on X-ray diffraction was achieved, using the synchrotron radiation source. The reflection patterns under various temperatures point out that La2Mo2O9 of low temperature form exhibits superlattice reflections, owing to its ordered oxygen vacancies. The low temperature form demonstrates more complex reflection patterns before (110), 2q=17.4°, than that of the high temperature form. Seven weak reflections that vanish after the phase transition are preliminarily identified as the superlattice reflections.
The ionic conductivity, between 300-800°C, was measured by AC impedance spectroscopy. We found that doping 10mol% Bi, Gd, and Ca can enhance the ionic conductivity at 800°C. Among the specimens of the 10mol% Bi, Gd, Ca doped La2Mo2O9 and undoped La2Mo2O9, the calcium doped specimen possess the highest ionic conductivity. The Arrhenius plot of ionic conductivity versus reciprocal temperature shows that the high temperature activation energy of undoped La2Mo2O9 is 8.9 kcal/mol, and the low temperature activation energy is 24.9 kcal/mol. The activation energy of 10mol% Bi is 29.8 kcal/mol. The high temperature activation energy of 10mol% Gd is 8.6 kcal/mol, and the low temperature activation energy is 34.9 kcal/mol. The high temperature activation energy of 10mol% Ca is 11.9 kcal/mol and the low temperature activation energy is 25.3 kcal/mol. The temperature dependence of ionic conductivity is generally higher in the low temperature region.
目錄
中文摘要………………………………………………………….Ⅰ
英文摘要………………………………………………………….Ⅲ
誌謝……………………………………………………………….Ⅴ
目錄……………………………………………………………….Ⅵ
圖索引……………………………………………………………Ⅹ
表索引…………………………………………………………ⅩⅣ
第一章 緒論………………………………………………...…1
第二章 文獻回顧與理論基礎………………….…………5
2.1 固態電解質…………………………………....…………5
2.1.1 高導電性之氧離子導體……………………………5
2.2 新的氧離子導體………………………………………..15
2.2.1 發現………………………………………………..15
2.2.2 b-La2Mo2O9之晶體結構…………………………….15
2.2.3 La2Mo2O9之氧傳導路徑……………………………16
2.3 離子運動能量障礙……………………………………..18
2.3.1 本質能隙(DHg)…………………………………….18
2.3.2 移動焓(DHm)……………………………………….20
2.3.3 捕陷能(DHt)……………………………………….22
2.4 離子導電率……………………………………………..23
2.5 交流阻抗分析原理……………………………………..26
第三章 實驗方法與步驟…………………………………..33
3.1 實驗流程圖……………………………………………..33
3.2 使用儀器設備與藥品…………………………………..34
3.3 陶瓷粉末之製備………………………………………..36
3.3.1 烘乾………………………………………………..36
3.3.2 陶瓷配粉與混粉…………………………………..36
3.3.3 煆燒與濕球磨……………………………………..37
3.4 成型與燒結……………………………………………..37
3.5 各類試片之製作與前處理……………………………..39
3.5.1 X-ray繞射光譜分析試片…………………………39
3.5.1-1 粉末繞射……………………………………..39
3.5.1-2 同步輻射光源(高強度光源)……………..39
3.5.2 掃描式電子顯微鏡顯微結構觀察………………...39
3.5.3 導電度量測之試片………………………………..40
3.6 性質測試………………………………………………..41
3.6.1 基本性質量測…………………………………….41
3.6.1-1 晶粒量測…………………………………….41
3.6.1-2 密度量測…………………………………….41
3.6.2 D.T.A熱分析……………………………………..42
3.6.3 X-ray繞射光譜分析………………..……………42
3.6.3-1 X-ray粉末繞射分析…………….………….42
3.6.3-2 同步輻射光繞射分析………………………42
3.6.4 導電率量測………………………………………43
第四章 結果與討論………………………………………..45
4.1 DTA熱分析…………………………………………..46
4.2 X-Ray繞射分析…………………………………….52
4.2.1 X光粉末繞射…………………………………54
4.2.2 同步輻射X光繞射分析(SRRC)……………59
4.3 燒結溫度與燒結體密度……………………………71
4.4 掃描式電子顯微鏡(SEM)微觀結構與晶粒尺
寸分析……………………………………………..73
4.5 導電率之量測………………………………………78
4.5.1 La2Mo2O9阻抗圖譜認定………………………..78
4.5.2 La2Mo2O9系列樣品離子導電率與活化
能之討論……………………………….………79
4.5.2(a) La2Mo2O9…………………….…...…79
4.5.2(b) (La1.8Bi0.2)Mo2O9…………….…..…82
4.5.2(c) (La1.8Gd0.2)Mo2O9………….……..…84
4.5.2 (d) (La1.8Ca0.2)Mo2O8.9……….………....86
第五章 結論…………………………………………….…89
參考文獻………………………………………….……….…91
附錄A…………………………………………………………..95
附錄B…………………………………………………………..96
參考文獻
1. S. C. Singhal, Science and Technology of Solid Oxide Fuel Cells, MRS Bulletin, March 2000.
2. F. Goutenoire, O. Isnard, E. Suard, O. Bohnke, Y. Laligant, R. Retoux, and P. Lacorre, J. Mater. Chem., 11, 119-124 (2001).
3. F. Goutenoire, O. Isnard, R. Retoux, and P. Lacorre,Chem. Chem. Mater., 12, 2575-2580 (2000).
4. P. Lacorre, F. Gouenoire, O. Bohnke, R. Retoux, Y. Laligant, Nature, 404, 856-858(2000).
5. A. R. West, Solid State Chemistry and Its Applications, Chap. 13, Wiley (1989).
6. T. H. Etsell, and S. N. Flengas, “The Electrical Properties of Solid Oxide Electrolyte“, Chemical Reviews, 70 [3] 339-376 (1970).
7. A. H. Heuer and L. W. Hobbs (editor), Science and Technology of Zirconia, Advances in Ceramics , Vol.3 , The American Ceramic Society (1981).
8. R. E. Carter and E. L. Roth , p.125-144, Electromotive Force Measurements in High Temperature Systems, Institution of Mining and Metallurgy, (1968).
9. J. G. Allpress and H. J. Rossell , J. Solid State Chem., 15 [1] 68-78 (1975).
10. B. Hudson and P. T. Moseley, J. Solid State Chem., 19, 383-389 (1976).
11. J. F. Baumard and P. Abelard, p.555-571, Defect Structure and Transport Properties of ZrO2-based Solid electrolytes, in Science and Technology of ZirconiaⅡ, edited by Claussen , Ruhel , Heuer, The American Ceramic Society, Ohio (1984).
12. J. C. Boivin and G. Mairesse, Chem. Mater., 10, 2870-2888 (1998).
13. M. Omari, M, Drache, P. Conflant, J. C. Boivin, Solid State Ionics, 40-41, 929 (1990).
14. N. Portefaix, P. Conflant, J. C. Boivin, J. P. Wignacourt, M. Drache, J. Solid State Chem., 134, 219 (1997).
15. J. C. Boivin and D. Thomas, Solid State Ionics, 3-4, 457 (1981).
16. J. C. Boivin and D. Thomas, Solid State Ionics, 5, 523 (1981).
17. P. Conflant, J. C.Bovin, G. Norwogrocki, D. Thomas, Solid State Ionics, 9, 925 (1983).
18. C. Y. Tsai, A. G. Dixon, Y. H. Ma, W. R. Moser, and M. R. Pascucci, J. Am. Ceram. Soc., 81 [6] 1437-1444 (1998).
19. Y. Zeng, Y. S. Lin, S. L. Swartz, J. Memb. Sci., 150, 87-98 (1998).
20. S. J. Xu and W. J. Thomson, Mater. & Interface, 3, 1289-1299 (1998).
21. X. Qi, Y. S. Lin, and S. I. Swartz, Ind. Eng. Chem. Res., 39, 646-653 (2000).
22. N. Trofimenko and H. Ullmann , Solid State Ionics, 124, 263-270 (1999).
23. V. V. Kharton, A. A. Yaremchenko, A. P. Viskup, G. C. Mather, E. N. Naumovich, F. M. B. Marques, Solid State Ionics, 128, 79-90 (2000).
24. T. Ishihara, T. Shibayama, M. Honda, H. Nishiguchi, and Y. Takita, J. Electrochem. Soc., 147 [4] 1332-1337 (2000).
25. Y. Larring and T. Norby, J. Electrochem. Soc., 147 [9] 3251-3256 (2000).
26. S. P. Jiang, J. P. Zhang, and K. Foger, J. Electrochem. Soc., 147 [9] 3195-3205 (2000).
27. V. V. Kharton, A. V. Kovalevvsky, A. P. Viskup, F. M. Figueiredo, A. A. Yaremchemko, E. N. Naumovich, and F. M. B. Marques, J. Electrochem. Soc., 147 [7] 2814-2821 (2000).
28. M. Mori, Y. Hiei, N. M. Sammes, and G. A. Tompsett, J. Electrochem. Soc., 147 [4] 1295-1302 (2000).
29. Y. Teraoka, H. M. Zhang, K. Okamoto, and N. Yamazoe, Mater. Res. Bull., 23, 51-58 (1988).
30. Y. Teraoka, T. Nobunaga, N. Yamazoe, Chem. Lett., 503-506 (1988).
31. S. Kim, S. Wang, X. Chen, Y. L. Yang, N. Wu, A. Ignatiev, A. J. Jacobson, and B. Abeles, J. Electrochem. Soc., 147 [6] 2398-2406 (2000).
32. K. Huang, R. S. Tichy, J. B. Goodenough, J. Am. Ceram. Soc., 81 [10], 2565-2575 (1998).
33. X. P. Wang and Q. F. Fang, J. Phys.: Condens. Matter, 13, 1641-1651 (2001).
34. J. B. Goodenough, “Crystalline Solid State Electrolytes Ⅱ:Material Design”; pp 43-73 in Solid State Electrochemistry edited by P. G. Bruce. Cambridge University Press, Cambridge , U. K., 1995.
35. Y. Teraoka, H. M. Zhang, S. Furukawa, and N. Yamazoe, Chem. Lett., 1743-1746 (1985).
36. 蔡英文,黃炳照 “同步輻射X光吸收光譜在鋰電池材料之應用”碩士學位論文 , 國立台灣科技大學(1999)
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