聚焦电子束辐照诱导单晶Si纳米线的选择性非晶化和新型同轴结构的形成  

Selective amorphization and novel coaxial structure formation of a single crystal Si nanowire induced by focused electron beam irradiation

作　　者：李锋[1,2] 苏江滨[3] 李论雄[4,5] 

机构地区：[1]厦门大学材料科学与工程系,福建厦门361005 [2]厦门大学中国-澳大利亚功能纳米材料联合实验室,福建厦门361005 [3]常州大学数理学院,江苏常州213164 [4]厦门大学化学系,福建厦门361005 [5]华南师范大学实验中心,广州510006

出　　处：《功能材料》2014年第3期79-82,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(11074207);国家重点基础研究发展计划(973计划)资助项目(2007CB936603);教育部高等学校博士学科点专项科研基金资助项目(20100121110023);国家科技计划国际科技合作与交流专项资助项目(2008DFA51230)

摘　　要：使用改进的原位透射电镜观察技术研究了室温下单晶Si纳米线在聚焦电子束辐照下的结构不稳定性。实验发现辐照区域内单晶Si纳米线外层会优先非晶化且局部径向膨胀,并随辐照剂量增加进一步形成新型3层包裹同轴结构等一系列有趣的变化。传统knock-on机制和电子束热效应并不能完全解释上述实验现象,然而利用最近提出的纳米曲率效应和电子束非热激活效应则能得到较好的解释。Structural instability of a single crystal Si nanowire at room temperature under focused electron beam irradiation was investigated by our developed in-situ transmission electron microscopy observation technique.It was observed that a series of intriguing changes such as preferential amorphization at the surface of Si nanowire, local bulging in the radial direction and formation of a novel three layers-packaged coaxial structure of Si nanowire with the increasing of electron doses during the irradiation.The possible mechanism for such phenome-na was proposed and further discussed by completely new concepts of nanocurvature effect and energetic beam-induced athermal activation effect,while the current knock-on mechanism and electron beam heating effect seemed inadequate to explain these processes.

关 键 词：SI纳米线 选择性非晶化 同轴结构 能量束非热激活效应 纳米曲率效应 

分 类 号：TB383[一般工业技术—材料科学与工程]