In situ observation of temperature-dependent atomistic and mesoscale oxidation mechanisms of aluminum nanoparticles  

作　　者：Jing Gao Jingyuan Yan Beikai Zhao Ze Zhang Qian Yu 

机构地区：[1]Center of Electron Microscopy and State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou,310027,China

出　　处：《Nano Research》2020年第1期183-187,共5页纳米研究（英文版）

基　　金：supported by the Chinese 1000-Youth-Talent Plan(for Q.Y.);111 project(No.B16042);the National Natural Science Foundation of China(No.51671168);the State Key Program for Basic Research in China(No.2015CB65930).

摘　　要：Oxidation is a universal process causing metals’corrosion and degradation.While intensive researches have been conducted for decades,the detailed atomistic and mesoscale mechanisms of metal oxidation are still not well understood.Here using in situ environmental transmission electron microscopy(E-TEM)with atomic resolution,we revealed systematically the oxidation mechanisms of aluminum from ambient temperature to^600℃.It was found that an amorphous oxide layer formed readily once Al was exposed to air at room temperature.At^150℃,triangle-shaped Al2O3 lamellas grew selectively on gas/solid(oxygen/amorphous oxide layer)interface,however,the thickness of the oxide layer slowly increased mainly due to the inward diffusion of oxygen.As the temperature further increased,partial amorphous-to-crystallization transition was observed on the amorphous oxide film,resulting in the formation of highly dense nano-cracks in the oxide layer.At^600℃,fast oxidation process was observed.Lamellas grew into terraces on the oxide/gas interface,indicating that the high temperature oxidation is controlled by the outward diffusion of Al.Single or double/multi-layers of oxide nucleated at the corners of the terraces,forming denseγ’-Al2O3,which is a metastable oxide structure but may be stabilized at nanoscale.

关 键 词：in situ transmission electron microscopy(TEM) aluminum oxidation temperature diffusion 

分 类 号：TB383[一般工业技术—材料科学与工程]