在本研究中，通過改變催化劑和四乙氧基矽烷(TEOS)前驅物添加量，使用溶膠-凝膠法成功地合成了披覆有SiO2核殼結構的Al2O3陶瓷粉末，並通過傅立葉轉換紅外光譜（FT-IR）和穿透式電子顯微鏡(TEM)圖像得到證實。透過TEM測量得知，SiO2殼層的厚度接近20 nm，可以通過增加TEOS添加量來增加厚度。 TEM-EDS元素分佈圖顯示，矽被披覆在氧化鋁奈米顆粒的表面上。
發現將燒結溫度提高到1300℃，可以提高那些核-殼結構樣品的收縮率和密度，並且掃描式電子顯微鏡（SEM）圖像也可以觀察到有較緻密的表面。通過X光繞射分析Al2O3核-殼的結構是六方晶的α-Al2O3剛玉。室溫介電性能測量結果表明，氫氧化鈉催化劑產物的介電性能優於氨催化劑產物。在本研究中，我們研究了核-殼結構的優勢具有降低燒結溫度的優勢，雖然Al2O3核-殼之樣品的介電性能仍較低於純Al2 O3的介電特性。
In this work, the Al2O3 ceramic powder coated with SiO2 core-shell structures have been successfully synthesized by modified catalyst and tetraethoxysilane (TEOS) precursor amount of sol-gel method, which have been checked by the Fourier-transform infrared spectroscopy (FT-IR) spectrum and Transmission electron microscopy (TEM) image. The thinness of SiO2 coating layer is near 20 nm and it can be increasing by increasing addition TEOS, which also have been measured by TEM picture. The element analysis of TEM-EDS mapping pictures are also showed that silicon is coated on the Al2O3 nano-particle’s surface.
The shrinkage and density of those core-shell structure samples can enhance by increasing sintering temperature to 1300oC, and the Scanning electron microscope (SEM) image also can observe dense surface of them. The structure of Al2O3-layer of core-shell is hexagonal α-Al2O3, which has been already analysis by X-ray diffraction. The room temperature dielectric property measurement is showed that dielectric property of sodium hydroxide catalyst products is better than it of ammonia catalyst products. In this work, we report that the advantage of core-shell structure can reduce sintering temperature, although the dielectric property of this core-shell sample is still less than it of pure Al2O3.
