以水熱法合成細顆粒鈦酸鋇，合成的溫度為75 ℃至180 ℃之間，合成時間為10分鐘至96小時，在強鹼的情況下進行水熱反應，使用的鋇源為氫氧化鋇，本研究是探討幾種不同的鈦源、溫度和時間對合成鈦酸鋇的影響，初步合成的鈦酸鋇粉末以X光繞射(XRD)鑑定結晶性結構，掃瞄式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)鑑定粒子大小及型態，由比表面積估算平均粒子大小。實驗結果顯示，不同的鈦源對鈦酸鋇粒子大小與型態有很大的影響，在120 ℃水熱反應24小時的條件下，以二氧化鈦(銳鈦礦結構,Merck)為鈦源合成出來的鈦酸鋇粒子最大，以二氧化鈦(70 ％銳鈦礦和30 ％金紅石，Degussa)或氫氧化鈦為鈦源時合成出來的鈦酸鋇粒子大小為0.1 μm，但是由穿透式電子顯微鏡的結果顯示，以氫氧化鈦為鈦源時合成出來的鈦酸鋇粒子與粒子聚集在一起而形成孔洞的結構。除此之外，粒子大小和型態與合成溫度有關，在85 ℃時，粉末的型態是由很小的結晶聚集在一起形成不同大小的團狀物，在180 ℃時，粒子大(大約130 nm)、均一接近單一分散，而延長反應時間，對粒子大小及型態並沒有重大的影響。 Barium titanate fine particles were prepared by hydrothermal synthesis. The synthesis was preformed at temperature between 75 ℃ and 180 ℃ and for 10 min-96 h. The reactions were carried out in a strong alkaline solution. Ba(OH)2?8H2O was used as the Ba-precursor material. The various Ti-precursors were used to investigate their effects on the properties of BaTiO3. The as-synthesized of BaTiO3 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption measurement, and differential scanning calorimetry (DSC). XRD showed that the as-synthesized of BaTiO3 powders have the BaTiO3 structure. SEM and TEM showed the particle size and morphology of BaTiO3. The average particle size of BaTiO3 was calculated from BET surface area. The type of precursor has strong influence on the size and the morphology of barium titanate. The particle size of BaTiO3 was the largest when synthesized at 120 ℃ for 24 h by using anataseTiO2 (Merck) precursor. The particle size was about 0.1 μm when using TiO2 (70 % anatase and 30 % rutile, Degussa P25) or Ti(OH)4 as the precursor. The morphology of powder was the porous structure when using Ti(OH)4 Ti-precursor. In addition, the particle size and morphology was dependent on synthesis temperature. At 85 ℃, the morphology of powder was small crystal and agglomerate of clusters. At 180 ℃, the morphology of powder was large (~130 nm), uniform and nearly monodisperse particles. The extending synthesis time has no significant influence on size and morphology.
