近年的研究顯示高熵材料不再僅限於金屬，高熵也可使多元陶瓷在高溫形成穩定的單一結構。先前研究提出的高熵氧化物為(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O，並證實此系統在高溫下是氯化鈉型結構的單一相，各元素分布均勻，且在不同溫度具單相與多相的可逆相變化。為了在有限的溫度區間觀察到較多現象，本研究採用化學法來製備高熵氧化物的粉末，成功將(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O的相轉換溫度降低。探討高熵氧化物方面，本研究嘗試減少(Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O的成分，發現(Mg0.25Ni0.25Cu0.25Zn0.25)O也符合高熵材料的條件與特性，並觀察到兩種高熵氧化物在低溫的析出相皆為氧化銅。接著量測上述兩個高熵陶瓷在單相與多相結構時的介電性質、微結構、價態、電阻率、以及活化能，比較並探討之間的差異，找出這兩個高熵陶瓷系統可能的應用。

Entropy-stabilized oxide systems with four and five cations have been synthesized by the thermal decomposition of a metal–nitrate–citrate complex at 800-925 °C. A five-component oxide (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O is found to exhibit a reversible transformation between a multi-phase and single-phase state at elevated temperatures. Experimental results show that the cations in the single-phase state with a rocksalt structure are distributed homogeneously. The phase transformation temperature is reduced for the powders synthesized by a wet chemical reaction route. Similar results are also observed in the four-component oxide (Mg0.25Ni0.25Cu0.25Zn0.25)O. Effects of chemical compositions and phase formation on physical properties of the above entropy-stabilized oxide systems are investigated.

第一章 前言-1
1.1 晶體結構與元素分佈-1
1.2 價數平衡機制-2
1.3 極高的介電常數-2
1.4 研究動機與內容-3
第二章 實驗步驟-4
2.1 原料-4
2.2 粉體合成-4
2.3 試片製備-4
2.4 X-ray繞射分析-5
2.5 微結構觀察-5
2.6 介電性質與阻抗分析-5
2.7 元素價態分析-6
2.8 熱重熱差分析-6
2.9 熱傳性質量測-6
第三章 結果與討論-7
3.1 物相分析-7
3.2 緻密程度觀測-7
3.3 熱擴散係數-8
3.4 介電常數-9
3.5 元素價態分析-9
3.5.1 銅離子-9
3.5.2 鎳離子-10
3.5.3 鈷離子-10
3.6 熱重熱差分析-10
3.7 低溫二次相分析-11
3.8 部分相圖-12
3.9 高溫單相微結構-12
3.10 低溫多相微結構-13
3.11 電阻率與介電損失-14
3.12 阻抗分析-15
第四章 結論-17
參考文獻-18

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