Gnanasekar K I, Jiang X, Jiang J C, Chu Deryn, Rambabu B
Surface Science, Spectroscopy and Solid State Ionics Laboratory, Department of Physics, Southern University and A&M College, Baton Rouge, Louisiana 70813, USA.
J Nanosci Nanotechnol. 2002 Apr;2(2):189-96. doi: 10.1166/jnn.2002.085.
Nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) has been successfully prepared by a solution chemical route. High-resolution transmission electron microscopy studies show that the average grain size of Sn0.8In0.2O2 heated at 310 degrees C, 500 degrees C, and 800 degrees C for 12 h is about 3-4 nm, 5-6 nm, and 7-10 nm, respectively. The corresponding values for pure SnO2 are 3-4 nm, 7-10 nm, and 50-90 nm, respectively. Powder X-ray diffraction and electron diffraction studies confirm the existence of solid solution only in the nanocrystalline state (the average particle size is in the range of 5-10 nm) with the solubility limited to 20% of In2O3. Indium ions stabilize the nanocrystalline nature of Sn1-xInxO2 (0 < or = x < or = 0.2) and prevent the grain growth by entering the SnO2 lattice. The thermal characteristics of nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) investigated by thermogravimetric (TG) and differential thermal analysis (DTA) show that the solid solution decomposes at 820 degrees C into SnO2 and In2O3, which is accompanied by a rapid crystal growth. The electrical conductivity and activation energy of Sn1-xInxO2 (0 < or = x < or = 0.2) undergo significant changes when the average grain size is less than or equal to 2 x the Debye length, LD.
通过溶液化学路线已成功制备出纳米晶Sn1-xInxO2（0≤x≤0.2）。高分辨率透射电子显微镜研究表明，在310℃、500℃和800℃下加热12小时的Sn0.8In0.2O2的平均晶粒尺寸分别约为3 - 4纳米、5 - 6纳米和7 - 10纳米。纯SnO2的相应值分别为3 - 4纳米、7 - 10纳米和50 - 90纳米。粉末X射线衍射和电子衍射研究证实，仅在纳米晶状态（平均粒径在5 - 10纳米范围内）存在固溶体，且In2O3的溶解度限制为20%。铟离子稳定了Sn1-xInxO2（0≤x≤0.2）的纳米晶性质，并通过进入SnO2晶格来阻止晶粒生长。通过热重分析（TG）和差示热分析（DTA）研究的纳米晶Sn1-xInxO2（0≤x≤0.2）的热特性表明，固溶体在820℃分解为SnO2和In2O3，同时伴随着快速的晶体生长。当平均晶粒尺寸小于或等于2倍德拜长度LD时，Sn1-xInxO2（0≤x≤0.2）的电导率和活化能会发生显著变化。
