CaCu3Ti4O12 化合物(簡稱CCTO)為鈣鈦礦立方晶系結構，此化合物令人訝異的是可在相當廣泛的溫度區間保持介電持平效應且具有相當高介電常數。一般鈣鈦礦結構會具有高介電來源，是由於離子位移所造成，經由紅外線光譜及Raman光譜量測，確定CCTO由離子位移所導致的鐵電現象是不存在。再經由粉末的中子繞射，此材料由35k至1273k皆為單一相，並沒有相變態發生。目前對於高介電現象的解釋，偏向於異質效應所引起。常見的鈦酸鍶或鈦酸鋇材料，能夠藉由能障效應而大幅提昇介電常數。由文獻中，可以發現CCTO隨著銅含量降低，介電常數也隨之下降。
　　本文目的就是想要瞭解，在不同銅含量之下，對CCTO的介電性質及顯微結構中，究竟是扮演怎樣的角色。

　　We describe the material, cubic perovskite CaCu3Ti4O12 (CCTO) , which exhibits a large dielectric response, the temperature-dependence of which has not been seen in any existing material to our knowledge. Dielectric constants for CCTO is found to be much higher than expected based on the dielectric polarizabilities of the constituent atoms, and this property seems not to be related to either underlying ferroelectric or relaxor behavior. X-ray diffraction and thermodynamic data argue against an explanation in terms of ferroelectricity, i.e. the collective ordering of local dipole moments.

　　It is known that addition of copper to BaTiO3 or SrTiO3 can lead to greatly enhanced dielectric constant through the barrier layer mechanism. We prepared samples of CCTO that were copper deficient, which might be expected to preclude a copper rich phase at the grain boundaries. It’s found that the copper deficiency does indeed result in a lower dielectric constant.

　　In this paper, we would like clarify the effect of Cu stoichiometry on the microstructure and dielectric behavior of CCTO.

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