本研究是以共沉澱法，利用氨水共沉澱硝酸鋁和硝酸鑭溶液來製備鋁酸鑭。我們改變氨水的添加量，其添加量為硝酸根莫耳數的0.5、1、1.5和5倍，來觀察對合成粉體的影響。同時以化學沉澱法進行單成分元素的沉澱、分析，然後以物理混合之方式混合鑭與鋁之沉澱物再來與共沉澱做比較。
    我們發現先用沉澱再物理混合的系統是分別形成氫氧化鋁與氫氧化鑭，而共沉澱則是形成鑭鋁氫氧錯合物。兩者在高溫處理後都會形成結晶之鋁酸鑭，但是利用共沉澱的方式其相態較單一，非結晶的雜質也較少，並且可以在較低的溫度下得到結晶之鋁酸鑭粉體。共沉過程中的氨水添加量會對乾燥粉體的組成造成改變，連帶的影響粉體整體的熱行為表現以及熱重損失。氨水對於這些變化的關係並不是線性，而是會隨著添加到達一最大值後產生相反的影響效能。氨水含量為硝酸根莫耳數1和1.5倍的條件下共沉澱鋁酸鑭前趨物粉體，經過700℃3小時的煆燒後即可得到結晶之鋁酸鑭粉體。

In the present study, crystalline LaAlO3 nanoparticles were synthesized at temperatures as low as 700 oC using a reverse precipitation technique.  The aqueous solution, containing the stoichiometric ratios of lanthanum nitrate and aluminum nitrate to form LaAlO3, was dropped in an aqueous solution of NH4OH to form the insoluble metallic salts.  The amount of NH4OH used were varied according to [NH4+ from NH4OH]/[NO3ˉ from total metallic nitrates] = 0.5, 1, 1.5, and 5.0, respectively.  After centrifugation and drying, the solid precursors were calcined at different temperatures and the resultant particles were characterized using x-ray diffractometry, thermogrametric analysis, differential thermal analysis, infrared spectroscopy, and transmission electron microscopy.  The results indicated that the solid precursors obtained by co-precipitating La3+ and Al3+ from the solution can transform to crystalline LaAlO3 at temperature much lower than those obtained by mixing the La3+-contained precipitates and Al3+-contained precipitates.  The amount of NH4OH used slightly affected the formation of LaALO3.  When [NH4+ from NH4OH]/[NO3ˉ from total metallic nitrates] was controlled at 1.5, the obtained solid precursor can decompose to form crystalline LaALO3 at 700 oC.

本文目錄
摘要						I
英文摘要						II
目錄						III
圖目錄						V
表目錄						VII


第一章 前言與研究動機                                   1
1-1 前言                                                1
1-2 研究動機                                            3
第二章 基本原理與文獻回顧                               4
2-1 介電原理                                            4
2-2 LaAlO3介紹                                         13
2-3 LaAlO3合成方法                                     15
2-3-1 固態合成法                                       17
2-3-2 溶膠-凝膠法                                      18
2-3-3 共沉澱法                                         20
2-3-4 檸檬酸鹽先驅物法                                 22
2-3-5 其他合成法                                       23
第三章 實驗步驟與特性分析                              25
3-1 實驗步驟                                           25
3-2 特性分析                                           28
3-2-1 X-ray繞射分析                                    28
3-2-2 傅立葉紅外線光譜分析                             29
3-2-3 穿透式電子顯微分析                               30
3-2-4 TG-DTA熱分析儀                                   31
第四章 結果與討論                                      33
4-1 起始原料特性分析                                   33
4-2 單成份化學沉澱分析                                 35
4-2-1 硝酸鋁沉澱物特性分析                             35
4-2-2 硝酸鑭沉澱物特性分析                             39
4-3 物理混合製備之鋁酸鑭特性分析                       43
4-4 共沉澱製備之鋁酸鑭特性分析                         48
4-5 共沉澱與物理混合之比較                             55
4-6 不同氨水添加量共沉澱鋁酸鑭之比較                   60
第五章 結論                                            72
第六章 參考文獻                                        74


圖目錄
圖2-1 極化機構種類圖                                   6
圖2-2 極化種類與頻率之關係圖                           7
圖2-3 (a)理想介電材料與(b)實際介電材料內電壓、電荷、電流與時間對應圖                                             8
圖2-4 電流電場之相位圖                                 10
圖2-5 (a)鋁酸鑭結構圖；(b)菱形晶系對應六方晶系結構圖   13
圖3-1 實驗流程圖                                       26
圖3-2 X光對晶格所產生之繞射                            29
圖4-1 硝酸鑭與硝酸鋁不同溫度煆燒3小時IR圖              34
圖4-2 AN-1.5N乾燥粉體TG-DTA圖                          35
圖4-3 AN-1.5N不同溫度煆燒3小時IR圖                     36
圖4-4 LN-1.5N乾燥粉體TG-DTA圖                          39
圖4-5 LN-1.5N不同溫度煆燒3小時IR圖                     40
圖4-6 LA-mix乾燥粉體TG-DTA圖                           43
圖4-7 LA-mix不同溫度煆燒3小時IR圖                      44
圖4-8 LA-1,1-1.5N乾燥粉體TG-DTA圖                      48
圖4-9 LA-1,1-1.5N不同溫度煆燒3小時XRD圖                49
圖4-10 LA-1,1-1.5N不同溫度煆燒3小時IR圖                50
圖4-11 全部粉體沉澱之TG-DTA圖                          55
圖4-12 不同方法製備樣品於不同溫度煆燒3小時XRD圖        58
圖4-13 不同方法製備樣品於不同溫度煆燒3小時IR圖         59
圖4-14 LA-1,1-0.5N不同溫度煆燒3小時XRD圖　　　　　　   61
圖4-15 LA-1,1-0.5N不同溫度煆燒3小時IR圖　　　　　　  　62
圖4-16 LA-1,1-0.5N乾燥粉體TG-DTA圖                     62
圖4-17 LA-1,1-1N不同溫度煆燒3小時XRD圖                 63
圖4-18 LA-1,1-1N不同溫度煆燒3小時IR圖                  63
圖4-19 LA-1,1-1N乾燥粉體TG-DTA圖                       64
圖4-20 LA-1,1-5N不同溫度煆燒3小時XRD圖                 64
圖4-21 LA-1,1-5N不同溫度煆燒3小時IR圖                  65
圖4-22 LA-1,1-5N乾燥粉體TG-DTA圖                       65
圖4-23 不同氨水比例沉澱粉體煆燒後TEM圖                 68
圖4-24 不同氨水添加量之樣品TG-DTA圖                    69


表目錄
表2-1 LaAlO3合成文獻表                                 15
表3-1 實驗藥品規格資料表                               27
表3-2 實驗儀器規格資料表                               32
表4-1 不同氨水添加比例之樣品粒徑表                     69
表4-2 不同氨水比例共沉粉體之化學組成表                 71

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