In/Nb共掺杂TiO_(2)薄膜结构特性的电子显微学研究

Microstructural characterization of(In/Nb)Co⁃doped TiO_(2) thin films by advanced electron microscopy

本文研究了In/Nb共掺杂TiO_(2)(TINO)薄膜在LaAlO_(3)(001)和m面α⁃Al_(2)O_(3)衬底上的生长行为和显微结构特征。研究发现TINO薄膜在LaAlO_(3)衬底上呈现锐钛矿结构(A⁃TINO),在m面α⁃Al_(2)O_(3)衬底上呈现金红石结构(R⁃TINO)。薄膜与衬底的晶体学取向关系分别为:(001)[100]A⁃TINO//(001)[100]LaAlO_(3)和(001)[100]R⁃TINO//(1100)[0001]α⁃Al_(2)O_(3)。通过原子分辨率扫描透射高角环形暗场像技术确定了A⁃TINO/LaAlO_(3)和R⁃TINO/α⁃Al_(2)O_(3)异质界面以及薄膜中孪晶和晶界的精细结构。本工作有助于理解TiO_(2)基薄膜的外延生长行为以及掺杂元素在材料中的偏聚特征。

The growth and microstructures of In/Nb co⁃doped TiO_(2)(TINO)thin films prepared on LaAlO_(3)(001)and m⁃planeα⁃Al_(2)O_(3)were investigated by advanced transmission electron microscopy(TEM).TINO thin films have an anatase structure(A⁃TINO)on LaAlO_(3)and a rutile structure(R⁃TINO)on m⁃planeα⁃Al_(2)O_(3).The film⁃substrate orientation relation was determined to be(001)[100]A⁃TINO//(001)[100]LaAlO_(3)and(001)[100]R⁃TINO//(1100)[0001]α⁃Al_(2)O_(3).By high⁃angle annular dark⁃field imaging of scanning TEM,the structural details of A⁃TINO/LaAlO_(3)and R⁃TINO/α⁃Al_(2)O_(3)heterointerface,twins,and grain boundaries were characterized at the atomic scale.Our findings provide a better understanding of the growth behavior of TiO_(2)⁃based thin films on various substrates and cation segregation in the doped TiO_(2)materials.