锡掺杂二氧化钛相变过程和微结构分析

Analysis of Phase Transformation Processing and Microstructure of Sn doped TiO_2

本文采用溶胶凝胶法制备了锡掺杂纳米二氧化钛,通过高分辨透射电镜法(HRTEM),X-射线衍射法(XRD)等分析手段对样品的相变过程进行了表征。XRD和HRTEM测试表明纯二氧化钛在烧结温度高于500℃时出现金红石相,而25mol%Sn2+掺杂二氧化钛凝胶在300℃烧结2 h后少量锐钛矿相析出的同时结晶出金红石相。实验结果表明Sn2+掺杂抑制了锐钛矿和金红石相的晶粒长大;Sn2+掺杂明显地促进了锐钛矿向金红石的转变。Sn2+氧化后形成Sn4+,Sn4+置换Ti4+而引起二氧化钛晶格膨胀的同时晶格畸变应力增加。

Sn doped TiO2 has been synthesized by sol-gel method characterized by high-resolution transmission electron microscopy （XRD）. The XRD and HRTEM results show that for the pure sintering temperature is above 500 ℃ ; but for the 25mol% Sn2＋ and the crystallization procedure was （HRTEM） and X-ray diffractometer titania, the rutile occurred when the doped titania, both the anatase and rutile were started to crystallize at 300 ℃ after sintered for 2 h. The results indicated that Sn2＋ doping inhibited the growth of the titania crystals; Sn2＋ doping significantly promoted the anatase to ruffle transformation. The Sn2＋ was oxidized to Sn4＋ and came into the TiO2 lattice to substitute the Ti4＋ and induce lattice expansion and increase of lattice distortion.