NSF: Direct Imaging of Charge Distribution in Ceramic Materials

NSF：陶瓷材料中电荷分布的直接成像

• 批准号: EP/F028784/1
• 负责人: Angus Kirkland
• 金额: $ 45.37万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF028784%2F1
• 关键词: NSF; Direct; Imaging; Charge; Distribution

If one knew the positions of all the electrons in a material, there would be no need to find where the nuclei are . This is a very strong statement, and whilst it may not true in all possible cases, for many materials it is. Whilst there have been developments in our ability to determine the local structure of materials at atomic resolution in projection almost all of these have focused on locating the atom positions. The more difficult problem of determining the positions of the electrons is much less well developed but, if possible would provide a new dimension of information in materials research. If successful, the potential application of this type of data is very wide ranging and includes studies of catalysis; as new dielectric, ferroelectric and in some cases magnetic devices and in oxygen transport membranes and fuel-cells; it is also critical to the understanding at the atomic level of many corrosion problems. These studies will also provide a rich seam of experimental data against which theoretical models can be compared and calibrated at far higher precision than is currently possible. Our proposed research therefore poses a Grand Challenge , namely the experimental determination of local charge distribution in ceramic materials at the nanoscale with particular reference to studies of individual defects. To understand the effects of charge distribution on material properties we intend to develop methods for directly imaging charge . In particular we wish to examine the redistribution of charge at surfaces and defects which are often crucial to materials properties and device performance. To achieve this we will develop experimental methods for imaging charge using both Scanning Tunneling Microscopy (STM) and aberration corrected High Resolution Transmission Electron Microscopy (HRTEM). We will also compare results from these two techniques which provide complementary information. This project will span two internationally leading institutions, one in the UK and one in the USA each of which has access to unique instrumentation and computation for this purpose. Each part of the proposal will deliver new general methodologies and we will utilize these in pioneering experiments involving a range of technologically important materials. Funding for this project will support two post doctoral research fellows working at each of the collaborating institutions together with travel costs to enable members of both research teams to work in the collaborating laboratories.

如果知道材料中所有电子的位置，就没有必要去找原子核了。这是一个非常强有力的陈述，虽然它可能不是在所有可能的情况下都是正确的，但对于许多材料来说是正确的。虽然我们在投影中以原子分辨率确定材料局部结构的能力有所发展，但几乎所有这些都集中在定位原子位置上。更困难的问题是确定电子的位置，但如果可能的话，它将为材料研究提供新的信息。如果成功的话，这种类型的数据的潜在应用是非常广泛的，包括催化的研究;作为新的电介质，铁电体和在某些情况下的磁性设备和氧传输膜和燃料电池;它也是至关重要的理解在原子水平上的许多腐蚀问题。这些研究还将提供丰富的实验数据，理论模型可以比目前更高的精度进行比较和校准。因此，我们提出的研究提出了一个巨大的挑战，即在纳米级陶瓷材料中局部电荷分布的实验测定，特别是对单个缺陷的研究。为了了解电荷分布对材料性质的影响，我们打算开发直接成像电荷的方法。特别是，我们希望研究电荷在表面和缺陷的重新分布，这往往是至关重要的材料性能和器件性能。为了实现这一目标，我们将开发实验方法，使用扫描隧道显微镜（STM）和像差校正高分辨率透射电子显微镜（HRTEM）成像电荷。我们还将比较这两种技术提供的互补信息的结果。该项目将跨越两个国际领先的机构，一个在英国，一个在美国，每个机构都可以使用独特的仪器和计算。提案的每一部分都将提供新的通用方法，我们将在涉及一系列技术重要材料的开创性实验中利用这些方法。该项目的资金将支持两名博士后研究员在每个合作机构工作，并支付旅费，使两个研究小组的成员能够在合作实验室工作。

项目成果

Optimized conditions for direct imaging of bonding charge density in electron microscopy

电子显微镜中键合电荷密度直接成像的优化条件

• DOI: 10.48550/arxiv.1008.4291
• 发表时间: 2010
• 作者: Ciston J

Shape transitions of epitaxial islands during strained layer growth: anatase TiO2(001) on SrTiO3(001).

• DOI: 10.1103/physrevlett.102.146102
• 发表时间: 2009-04
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: M. Marshall;M. R. Castell