锰掺杂诱导正交相SnO_2的生长行为

Growth Behavior of Orthorhombic SnO_2 Induced by Mn-Doped SnO_2

通过一种简单的共沉淀方法制备了Mn掺杂二氧化锡(SnO_2)颗粒,对前驱体在不同温度下热处理,并通过X射线衍射(X-my diffraction,XRD)和高分辨电子显微学(high-resolution transmission electron microscopy,HRTEM)对样品的微纳米结构进行了表征.结果表明:样品中除了四方相Sn02外,还存在正交相SnO_2.XRD测试结果显示,随着退火温度的增加,正交相SnO_2的峰强减弱,四方相的峰强增加.HRTEM分析表明:样品中可以同时找到四方相和正交相SnO_2的晶格像,进一步证实了正交相SnO_2的存在.Mn掺杂SnO_2后,Mn离子进入SnO_2晶胞,替代了Sn离子,因此引起晶格扭曲畸变,对正交相SnO_2的形成起着重要的作用.

Tin dioxide （SnO2） is an n-type semiconductor material with tetragonal rutile crystal structure under normal conditions and displays many interesting physical and chemical properties. Another form of SnO2 with an orthorhombic crystal structure is known to be stable only at high pressures and temperatures. However, there are limited reports on effects of Mn-doped tetragonal phase SnO2 on micro/nanostructured characteristics. In this article, micro/nanostructures of Mn-doped tetragonal phase SnO2 have been successfully prepared with a chemical co-precipitation method. The micro/nanostructural evolution of Mn-doped tetragonal phase SnO2 under different heat treatment temperatures is evaluated with X-ray diffraction （XRD） and a high-resolution transmission electron microscopy （HRTEM）. It is surprisingly found that the orthorhombic phase SnO2 is formed in Mn-doped tetragonal phase SnO2 . The obvious diffraction peaks and clear lattice fringes confirm that the orthorhombic phase SnO2 nanocrystals evidently exist in Mn-doped SnO2 samples. Experimental results indicate that the XRD peak intensities and crystal planes of the orthorhombic phase SnO2 decrease with increasing of heat treatment temperatures. Formation of orthorhombic phase SnO2 is attributed to the lattice distortion of tetragonal phase SnO2 due to the Mn-doped tetragonal phase SnO2.