CaCu3Ti4O12為類似鈣鈦礦立方晶結構的介電材料，在室溫下具有極高的介電常數，約105~106，並且在相當廣泛的溫度區間有介電持平的效應，因此引起各界關注。但是關於造成CaCu3Ti4O12特殊介電性質的真正原因仍然無法確定，目前較為眾人接受的論點是以Maxwell-Wagner Model來解釋，認為CaCu3Ti4O12內包含半導性的晶粒以及絕緣性的晶界[1~4]，但上述論點並無法解釋為何CaCu3Ti4O12的單晶也具有巨大的介電常數值，而本實驗室在CaCu3Ti4O12中觀察到次晶粒的存在[5]，因此認為在單晶中，次晶粒與其邊界的異質結構也可能使CaCu3Ti4O12具有巨大介電常數值。
　　本研究主要是藉由觀察CaCu3Ti4O12在不同熱腐蝕條件下的顯微結構來探討CaCu3Ti4O12的次晶粒形成原因。為了瞭解CaCu3Ti4O12的導電機制，我們也利用XPS來分析CaCu3Ti4O12內的金屬離子價數，但由前人文獻[44]中指出銅離子處於真空狀態會發生變化，因此本研究也會針對抽真空前後的實驗結果來比較。最後，本研究將分析摻雜Si後的CaCu3Ti4O12與CaCu3Ti4O12的J-E特性曲線，來觀察其導電行為的差異，來找出影響CaCu3Ti4O12導電機制的主要原因，並觀察是否與其介電機構也有關連。

　　CaCu3Ti4O12 is a dielectric material which has cubic pervoskite-related structure. This material has attracted considerable attention because it has ultrahigh dielectric constant (about 105~106) at room temperature and good temperature stability over a wide temperature range. It can be explained using the barrier model of CaCu3Ti4O12 consists of semiconducting grains and insulating grain boundaries, However, the origin of colossal dielectric constant in CaCu3Ti4O12 is still remains unresolved. Fang observed subgrains in CaCu3Ti4O12[5] suggested that subgrains might be the origin responsible for the dielectric response inside single grain CaCu3Ti4O12.
In this study, first of all, the formation mechanism of subgrains by thermal-etching under different conditions is a priority. Second, XPS has been taken advantage of researching the valances of metal ions for understanding the conduction mechanism in CaCu3Ti4O12, but it should be taken care that the valences of copper species in copper oxides had been known to be varied during vacuum annealing[44]. At least, the comparison of conduction behavior in CaCu3Ti4O12 with Si doped to pure CaCu3Ti4O12 has been discussed.

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