（毕业学术论文设计）-钛酸铋钠铁电薄膜掺杂研究.doc

PAGE 毕业论文 题 目 Na0.5Bi0.5TiO3铁电 薄膜的掺杂改性研究 学 院 材料科学与工程 二〇一一 年 六 月 十 日 摘 要 我们采用化学溶液分解法制备了(Na0.7K0.2Li0.1)0.5Bi0.5TiO3前驱体溶液，并在LaNiO3/Si和(Ba,Sr)(Ti,Mn)O3/Si两种衬底上分别制备了(Na0.7K0.2Li0.1)0.5Bi0.5TiO3薄膜。X－射线衍射图谱显示：(Na0.7K0.2Li0.1)0.5Bi0.5TiO3薄膜具有良好的结晶性，值得注意的是在(100)取向LaNiO3衬底上制备的(Na0.7K0.2Li0.1)0.5Bi0.5TiO3薄膜表现出了(100)择优取向。(Na0.7K0.2Li0.1)0.5Bi0.5TiO3薄膜的厚度大约为220～230nm。为了进行电学性能测试，我们分别制备了金属-铁电薄膜-绝缘体-硅和金属-铁电薄膜-金属结构。Au/ (Na0.7K0.2Li0.1)0.5Bi0.5TiO3/(Ba,Sr)(Ti,Mn)O3/Si/Au的电容－电压曲线是逆时针的，为极化型存储方式；在±15V的偏电压下，电容－电压曲线的记忆窗口最大，约为3.97V。Au/(Na0.7K0.2Li0.1)0.5Bi0.5TiO3/LaNiO3结构的电容-电压曲线为典型的“蝴蝶”形。(Na0.7K0.2Li0.1)0.5Bi0.5TiO3铁电薄膜在LaNiO3和(Ba,Sr)(Ti,Mn)O3衬底上的积累态介电常数分别为300和220。 关键词：化学溶液分解法；Na0.5Bi0.5TiO3掺杂；铁电薄膜；电学性能 ABSTRACT We prepared the (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 precursor solution by a chemical solution decomposition method and deposited (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 films on LaNiO3/Si and (Ba,Sr)(Ti,Mn)O3/Si by spin-coating. The XRD patterns of (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 on two substrates showed that (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 films are crystalline. Note that (Na0.7K0.2Li0.1) 0.5Bi0.5TiO3 on (100)-LaNiO3 has preferred (100) orientation. The thicknesses of (Na0.7K0.2Li0.1) 0.5Bi0.5TiO3 films are about 220～230nm. For electrical measurements, we prepared metal-ferroelectric films-insulator-silicon and metal-ferroelectric-metal capacitors. The C-V curves of Au/(Na0.7K0.2Li0.1)0.5Bi0.5TiO3/(Ba,Sr)(Ti,Mn)O3/Si/Au exhibit anticlockwise direction, indicting the memory type is polarization. The maximum memory window is 3.97V when the sweeping voltage is ±15V. The C-V curves of (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 on LaNiO3 have typical butterfly pattern. The dielectric constants of (Na0.7K0.2Li0.1)0.5Bi0.5TiO3 on LaNiO3 and (Ba,Sr)(Ti,Mn)O3 at the accumulate states are 300 and 220, respectively. Key words: Chemical solution decomposition; (Na0.7K0.2Li0.1)0.5Bi0.5TiO3; ferroelectric thin films; electrical property 目