Pb（Fe2/3W1/3）O3（PFW）是強電性弛緩體材料，具有無序的鈣鈦礦結構 ，亦即Fe3+和W6+離子在結構中八面體位置（octahedral site）任意的排列，是已知的低溫多層陶瓷電容材料之一。

經由液相燒結的PFW陶瓷，呈現晶核與晶殼結構，其中晶核是Fe豐富的區域，而晶殼是W豐富的區域，長時間的熱處理，晶粒會藉由擴散來達成晶粒內晶核與晶殼成份濃度的均質化。本論文藉由TEM的觀察與EDS的分析，來說明長時間熱處理，晶核-晶殼間成份濃度的變化

一般認為A（B1 , B2）O3鈣鈦礦系統的有序結構來自於B-site離子的有序排列，無論晶核或晶殼都出現F-spot（超晶格繞射（1/2 1/2 1/2）），表示晶核或晶殼都在做某種程度的有序排列，因此Fe與W的排列方式或是空缺的形式，都可能是F-spot（超晶格繞射（1/2 1/2 1/2））生成的原因。

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一、 緒論………………………………………………..1
1-1前言……………………………………………1
1-2本研究之重點及目的…………………………2
二、 文獻回顧………………………………………….3
2-1強電性陶瓷材料………………………………3
2-2弛緩體………………………………………..6
2-2-1弛緩體簡介…………………………..6
2-2-2有序-無序(order-disorder)結構………10
2-3擴散式的相變化(DPT)………………………..14
2-3-1 擴散式相變化的定義…………………14
2-3-2 擴散式相變化的生成機構模型………15
2-4 晶核-晶殼(Core-Shell) 結構………………….18
2-4-1 core-shell 結構簡介…………………….18
三、 實驗步驟及方法…………………………………20
3-1粉體製備…………………………………………20
3-2 顯微組織觀察……………………………………20
3-2-1 X光繞射分析…………………………….20
3-2-2 SEM顯微結構觀察………………………21
3-2-3 TEM顯微結構觀察………………………21
3-3 密度測量方法……………………………………22
3-3-1 理論密度………………………………….22
3-3-2 阿基米德法測量密度…………………….22
四、 實驗結果…………………………………………….26
4-1 密度………………………………………………26
4-2 X-ray結果………………………………………..26
4-3 SEM結果…………………………………………27
4-4 TEM觀察………………………………………...37
五、 討論………………………………………………….53
5-1 Core-shell結構的型態………………………….53
5-2 Core-shell 的生成原因………………………….54
5-3 Core-shell 結構與DPT的關係………………..61
5-4 F-spot的成因……………………………………61
六、 結論…………………………………………………..64
References…………………………………………………65
Appendix

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