工艺参数对形成（Pb,La）TiO3溶胶和凝胶的影响

系统地研究了溶胶－凝胶技术制备Ｐｂ（１－ｘ）ＬａｘＴｉ（１－ｘ／４）Ｏ３的铁电陶瓷膜时催化剂、溶液浓度在室温下对形成溶胶和凝胶的影响规律；用约外光谱研究了成胶机理；用该技术成功地在（１００）Ｓｉ单晶衬底上制备出了均匀、无裂纹且具有钙铁矿结构的ＰＬＴ晶态薄膜。

On Gelation Mechanism of Formation of (Ph,La)TiO_3 Sol-Gel

To our best knowledge, there still does not exist any theoretical explanation about suitable ranges of values of solution concentration and amount of acetic acid for making (Ph, La)TiO3 (PLT ) Sol-Gel. We now present the results of our systematic study and the rangesthat are suitable; then we give theoretical explanation. As shown in Tables 1 through 4,when the solution concentration is from 0. 3 to 0.7 mol, and when pH value is from 3 to 4.5,we obtain clear Sol and transparent Gel. In addition, the above ranges will become narrowerwith the addition of La. All the above results are now explained with the gelation mechanismwe propose in this paper. From Fig. 1 we can see that there is no chemical reaction and consequently no new Alkoxide formation. By comparing subfigures f, g and h of Fig. 2, we findthat during the process of gelation, only Ti(OC4H9)4 hydrolyzes and condenses gradually Soby adjusting the amount of acetic acid, we can control the velocity of hydrolySis and condensation of Ti (OC4H9)4. By using Sol-Gel spin-on technique, Ph(1-x) La(x)Ti(1-x/4)O3 (x=0.06-0.22) thin films with percys kite structure are successfully prepared, on (100) singlecrystal silicon substrates. The thickness of them is from 200 to 600 um.