Nanoscience under extreme forces

极端力量下的纳米科学

• 批准号: 6594-2013
• 负责人: Kreuzer, Juergen
• 金额: $ 3.21万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=544362
• 关键词: Nanoscience; under; extreme; forces

At the atomic level matter can be modified by the application of large forces in particular by large external electrostatic fields. In such fields chemical effects come into play because the electronic orbitals get distorted to such a degree that the chemical characteristics of an atom or molecule become altered. In this way, new pathways in chemical reactions may be established. Examples of technological relevance are field evaporation in the field ion microscope that is used in Atom Probe Tomography (APT) to map the composition of an alloy atom by atom and layer by layer. The quantum mechanical theory of field evaporation of metals was developed in the late 1980s by my group and others. Recently it has become of interest to use ATP for the study of oxides. However, as an expert in the field, Bernard Deconihout, recently stated "Although APT has provided a large number of results on a wide panel of materials, interpretation of 3D images are sometimes difficult due to a lack in the understanding of the different evaporation mechanisms involved in semiconductors and oxides". We will make a systematic study of APT for insulators, in particular oxides. The benefits to APT will be substantial as our recent pilot project on MgO already showed.

在原子水平上，物质可以通过施加较大的力，特别是较大的外部静电场来改变。在这样的领域中，化学效应开始发挥作用，因为电子轨道被扭曲到一个原子或分子的化学性质被改变的程度。通过这种方式，可以建立化学反应的新途径。技术相关性的例子是场离子显微镜中的场蒸发，该显微镜用于原子探测层析(APT)，以逐原子和逐层地绘制合金原子的成分。金属场蒸发的量子力学理论是在20世纪80年代末由我的团队和其他人发展起来的。最近，利用三磷酸腺苷来研究氧化物已引起人们的兴趣。然而，作为该领域的专家，Bernard Deconihout最近指出，尽管APT提供了大量关于各种材料的结果，但由于缺乏对半导体和氧化物所涉及的不同蒸发机制的了解，3D图像的解释有时很困难。我们将对绝缘子，特别是氧化物的APT进行系统的研究。正如我们最近关于氧化镁的试点项目所表明的那样，APT将获得巨大的好处。