鈦酸鋇具有良好的介電性質，因此在工業上廣泛應用於被動元件、熱敏電阻器、溫度感測器等多種高容電子產品。為了使製成的電子元件能符合工業規格需求 (Y5V、X8R、X9R 等)，通常在鈦酸鋇中加入添加物，進行離子置換以改變介電常數變化率隨溫度改變的特性。本研究以鈦酸鋇為基礎，選擇氧化釔 (1.0 mol% , 3.0 mol%) 及氧化鎂 (0.5 mol% , 1.0 mol%) 作為添加，瞭解釔離子及鎂離子進入 Ti-site 後對於顯微結構、晶體結構與介電性質之影響，並以獲得高緻密度且小晶粒之殼-核結構之陶瓷體為目的。
　　實驗結果顯示，單一添加系統中，添加 3 mol% 氧化釔抑制燒結，令燒結溫度提高，添加氧化鎂促進燒結且提高陶瓷體之相對密度，並獲得較平坦的溫度-電容曲線 (TCC)。透過晶格計算得知，鎂離子進入 Ti-site 後，單位晶格的 a 軸伸長、c 軸縮短。當添加氧化釔則使 a 軸和 c 軸些微延長。在共添加系統中， 0.5Mg1Y 、 1Mg1Y 、0.5Mg3Y 和 1Mg3Y 樣品在 1300℃ 持溫 3 小時，獲得相對密度 90 % 以上的燒結體， 0.5Mg3Y 樣品的晶粒大小約在 1.0 μm - 2.0 μm 之間。

Due to the great performance of dielectric properties, barium titanate was used in great number of high-K capacitor products, such as passive devices, thermistors, and temperature sensors. To make electric device achieve the industrial specifications (Y5V, X8R, X9R, etc), we usually added additives into the barium titanate proceeding ion exchange to adjust the dielectric constant with temperature. The core-shell structure was obtained by Y2O3 and MgO doped into Ba-rich BaTiO3-based material. In this study, we investigated the microstructure, crystal structure and dielectric properties.
Doping 3 mol% Y2O3 can suppress its sintering shrinkage of BaTiO3 bulk. The addition MgO into BaTiO3 can enhance sintering shrinkage and acquire a flatter TCC curve. The tetragonality decreased as the amount of MgO increased.
The ceramic densities of 0.5Mg1Y, 0.5Mg3Y, and 1Mg1Y specimens sintered at 1300oC/ 3h were more than 90%, and the grain sizes of 0.5Mg3Y were between 1.0 μm - 2.0 μm.

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