本研究嘗試開發一個簡單、快速且可大量生產的三階段製程製備四氧化三鐵中空球複合結構。所製備的中空複合結構以電子顯微鏡及電子能量損失能譜探討各階段所得樣品之表面型態、晶體結構並進行氧化鐵之相鑑定。實驗結果顯示第一階段的噴霧裂解法所製備的氧化鐵中空球尺寸介於0.5至3微米，平均殼層厚度約為20奈米。所製備之中空球以Ar/H2氣氛進行還原可成功得到具有良好鐵磁特性的F四氧化三鐵結構。第二階段的溶膠-凝膠法所披覆的二氧化矽薄層厚度約為10奈米。第三階段的初濕含浸法所成長的銀顆粒尺寸約為10至30奈米，均勻分布在中空球表面。但電子能量損失能譜分析指出，四氧化三鐵中空球在經過成長銀顆粒的製程後部份被氧化，導致飽和磁化量下降。
最後探討此中空複合結構之表面增強拉曼光譜特性。與文獻中的實心球複合結構相比，以R6G為偵測物，在R6G濃度為10-8M時，此中空複合結構在1650cm-1處所得到的拉曼光譜強度較文獻中的高一個數量級以上。增強的原因推測與中空結構所提供的懸浮特性以及適當的銀顆粒尺寸及間距有關。

This study attempts to develop a simple, rapid and mass-produced three-stage process for the preparation of Fe3O4 hollow sphere composite structures. The prepared hollow composite structure was characterized by electron microscopy and electron energy loss spectroscopy to study the surface morphology and crystal structure of the samples obtained in each stage and to identify the phases of iron oxide. The experimental results show that the iron oxide hollow spheres prepared by the first stage spray lysis method have a size of 0.5 μm to 3 μm and an average shell thickness of about 20 nm. The prepared hollow spheres were reduced in an Ar/H2 atmosphere to successfully obtain a Fe3O4 structure having good ferromagnetic properties. The thickness of the SiO2 layer coated by the second stage sol-gel method is about 10 nm. The Ag particles grown in the third stage of the incipient wetness method have a size of about 10 to 30 nm and are uniformly distributed on the surface of the hollow sphere. However, the electron energy loss spectrum analysis indicates that the Fe3O4 hollow sphere is partially oxidized after the process of growing Ag particles, resulting in a decrease in the saturation magnetization.
Finally, the surface-enhanced Raman spectroscopy properties of the hollow composite structure are discussed. Compared with the solid sphere composite structure in the literature, with R6G as the detector, the Raman spectral intensity of the hollow composite structure at 1650 cm-1 is more than an order of magnitude higher than that in the literature when the concentration of R6G is 10-8M. The reason for the enhancement is presumed to be related to the suspension characteristics provided by the hollow structure and the appropriate Ag particle size and spacing.

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