Materials World Network: Measurement of Local Charge Distributions in Materials

西北大学的材料世界网络奖是为了合作研究开发必要的实验方法和理论框架，以直接在原子水平上对一系列技术上重要的氧化物材料中的电荷分布进行成像。这些材料广泛用于催化;作为新的电介质，铁电体和在某些情况下的磁性器件，并在氧传输膜和燃料电池;他们也是在许多腐蚀问题的关键。 传统的电荷测量是用钝仪器进行的，这必然会导致平均值，而平均值通常与原子尺度上性质不同的材料和器件无关。因此，为了理解电荷分布对材料性质的影响，有必要直接开发用于成像电荷的方法。因此，本建议的目的是开发实验方法，电荷成像使用扫描隧道显微镜和高分辨率透射电子显微镜和电子衍射，并从这些相关的结果。该计划将汇集两个研究小组在西北大学和牛津大学，英国互补的技能和独特的仪器：双像差校正透射电子显微镜在牛津和超高真空透射电子显微镜在西北以及扫描隧道显微镜在牛津的免费工具。除了通过电子邮件和视频会议（包括利用接入网格设施）进行传统的信息交流外，还将有年轻科学家和博士生的互访。作为合作研究的一部分开发的程序将公开提供。

This Materials World Network award to Northwestern University is for collaborative research to develop the experimental methodology and theoretical framework necessary to directly image charge distribution at the atomic level in a range of technologically important oxide materials. These materials are used extensively in catalysis; as new dielectric, ferroelectric and in some cases magnetic devices and in oxygen transport membranes and fuel-cells; they are also critical in many corrosion problems. Conventional measurements of charge are carried out with blunt instruments which necessarily result in average values that are often not relevant for materials and devices where properties vary on the atomic scale. Hence, in order to understand the effects of charge distribution on material properties it is necessary to direct develop methods for imaging charge. This proposal therefore aims to develop experimental approaches to charge imaging using both Scanning Tunneling Microscopy and High Resolution Transmission Electron Microscopy and electron diffraction and to correlate results from these. This program will bring together two research groups at Northwestern University and Oxford University, Great Britain with complementary skills and unique instrumentation: a double aberration-corrected transmission electron microscope in Oxford and an ultra-high vacuum transmission electron microscope at Northwestern as well as the complimentary tool of scanning tunneling microcopy in Oxford. In addition to conventional exchange of information via email and videoconferencing (including the utilization of access grid facilities), there will also be exchange visits by junior scientists and doctoral students. The programs that are developed as part of the collaborative research will be made publicly available.