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学术活动 |
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| “凝聚态物理-中关村论坛”第
181
次讲座 |
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| 题目: |
Seeing Invisible: A Spectral Panorama Looking into Materials’ Optical Properties at Nanometer Scale |
| 时间: |
2010年04月07日 10:30 |
| 地点: |
中科院物理所D楼212报告厅 |
| 报告人: |
谷林 博士 |
东北大学原子分子材料科学高等研究机构
个人简介
谷林，中国清华大学材料科学与工程系工学学士（2002）；美国亚利桑那州立大学材料科学与工程学院理学博士（2005）。2006年起，先后在德国马普金属所，日本东北大学先进材料研究所担任研究助理。长期从事电子显微学，光谱学前沿课题的研究，世界上首次实现了严格意义上高能量分辨率能量过滤扫描透射显微术。获得国际电子显微学联合会青年科学家奖。
报告摘要
Despite that various accesses have claimed a sub-50nm spatial resolution in detection of materials’ optical characteristics; transmission electron microscopy (TEM) in association with advanced valence electron energy-loss spectroscopy (VEELS) remains the choice for its inherently high spatial resolution approaching λ/40, where λ represents the excitation wavelength. Distinct from photons, fast electrons used in TEM are able to provide sufficient momentum transfer, allowing optical transitions that otherwise require compensation of the corresponding momentum by materials. Taking advantages of the newly developed electrostatic Ω-type monochromator and the high-dispersion, high-isochromaticity MANDOLINE filter, 2-dimensional mapping of single-electron excitations, i.e. band transitions, and collective excitations, e.g. volume-, surface- or interface- plasmons, becomes feasible. Applications of VEELS techniques to material sciences and the respective limitations are also discussed in this talk.
联 系 人：李 泓 研究员（82648067） |
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