三维TiO2枝晶中二级分枝的取向特征

Orientation characterization of secondary branches in three-dimensional TiO_2 dendrite

运用微束电子衍射(μ衍射)及高分辨电子显微术(HRTEM),系统研究了TiO2纳米二级枝晶的晶体取向特征。根据μ衍射调整并分析二级枝晶的取向,通过HRTEM像及相应的快速傅立叶变换(FFT)图,对经过取向选择的枝晶进行取向关系表征。本文发现三维TiO2枝晶中相邻的纳米二级次枝之间具有<010>I∥<011>II的取向特点。从取向分析结果推导出相邻的次枝分别在干枝的{101}及{001}晶面上沿<001>方向定向排列生长。基于该结果,讨论了这种定向排列的二级枝晶的生长机制。

Crystallographic orientation relationship of nanoscale branches of TiO2 was systematically investigated by micro diffraction pattern and high resolution transmission electron microscopy（HRTEM）.The orientation of the specimen was identified according to the micro diffraction pattern.On the basis of HRTEM observation and the corresponding Fast Fourier Transform（FFT） images,the orientation relationship between two neighboring branches in three-dimensional TiO2 dendrite was determined as 010 I∥ 011 II.This result indicated that the neighboring branches were grown from {101} and {001} planes of the trunk along 001 direction.The growth mechanism of the branches was discussed based on the orientation relationship.