Surface magnetic and structural properties studied with metastable de-excitation spectroscopy.

使用亚稳态去激发光谱研究表面磁性和结构特性。

• 批准号: EP/D034604/1
• 负责人: Steven Tear
• 金额: $ 36.57万
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FD034604%2F1
• 关键词: Surface; magnetic; structural; properties; studied

The structure and properties of the topmost atomic layer of a material become increasingly significant when ever smaller amounts of the material are used to make devices. Sometimes the electronic and magnetic properties of the surface can be very different from those of the underlying material, and difficult to predict. This work will answer questions about some material systems which we know are unusual, and we know how to create them, but without a complete understanding of their properties they cannot be fully exploited for technological applications. For example what is the difference in the surface structure of silicon atoms between 2- and 3-Dimensional rare-earth silicides? Do the exceptional magnetic properties of small clusters of atoms originate from the bulk or the surface? We will use a variety of techniques to measure these properties, but in particular metastable de-excitation spectroscopy. In a unique instrument, excited (metastable) helium atoms are focussed onto the surface of interest using laser-cooling methods. Approaching to within a few Angstroms of the surface, the energy of the atoms is released, liberating electrons from the sample with an energy spectrum characteristic of the electronic, structural and magnetic properties of the surface, and not confused by contributions from underlying atoms.

当用于制造器件的材料数量越来越少时，材料最上层原子层的结构和性质变得越来越重要。有时，表面的电子和磁性能与底层材料的性质大不相同，很难预测。这项工作将回答一些我们知道不寻常的材料系统的问题，我们知道如何创造它们，但如果没有对它们的性质的完全理解，它们就不能被充分利用于技术应用。例如，二维和三维稀土硅化物的硅原子表面结构有什么不同？小簇原子的特殊磁性是来自于体积还是表面？我们将使用各种技术来测量这些性质，但特别是亚稳去激发光谱。在一种独特的仪器中，激发（亚稳态）氦原子使用激光冷却方法聚焦到感兴趣的表面。在接近表面的几埃范围内，原子的能量被释放，从样品中释放出具有表面电子、结构和磁性的能谱特征的电子，并且不会被底层原子的贡献所混淆。

项目成果

Enhanced Surface spin-polarisation of Fe Nanoclusters

Fe 纳米团簇的增强表面自旋极化

• 发表时间: 2010
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: N/a Pratt

Fe nanoclusters on ZnO tetrapods

ZnO 四足体上的 Fe 纳米团簇

• 发表时间: 2010
• 期刊: Nat. Materials
• 作者: N/a Pratt