11/4 研究科セミナー (IBM & Leiden University: Rudolf M. Tromp 氏)

 

マテリアルサイエンス研究科4棟8階 中セミナー室 13:30-15:00

「Recent Developments in Cathode Lens Microscopy」

IBM T.J. Watson Research Center & Leiden Institute of Physics, Leiden University
Prof. Dr. Rudolf M. Tromp

講演要旨
 Cathode lens microscopy, comprising both Photo Electron Emission Microscopy (PEEM) and Low Energy Electron Microscopy (LEEM), has undergone major developments over the last decade. This includes correction of spherical and chromatic aberration, the increasing use of PEEM for spatially resolved k-space imaging of occupied electron bands, and -most recently- the use of LEEM for spatially resolved k-space imaging of un-occupied electron bands. Correction of spherical and chromatic aberration is now becoming more broadly available, and had distinct advantages for use in synchrotron-based PEEM. However, setup of optimum imaging conditions for a given experiment is still open to discussion. I will show how the electron mirror optics, in combination with the objective lens, can be configured as an adjustable achromat. For example, an achromat centered around a start energy of 2.5 eV, with a bandwidth of 5 eV, yields a spatial resolution of 4-5 nm, while an achromat centered at 30 eV, with a passband from 9 to 62 eV has a resolution of 15 nm. Such a very wide passband (resulting in high transmission) may be extremely useful for imaging samples with weak signals, as often encountered in practice. I will also discuss the prospects for developing an apochromatic system, which would further improve resolution by another factor 2x, and transmission by a factor 10x. Finally, I will show recent
results on measuring un-occupied band structures by LEEM, yielding information complementary to traditional ARUPS experiments.

講演者略歴
1978 Physics Engineer, the Twente University of Technology
1982 PhD in Physics, Utrecht University
1983-present Research Scientist, IBM T.J. Watson Research Center
2002 IFCAM Professor, IMR, Tohoku University
2006-present Professor, Leiden Institute of Physics, Leiden University

担当教員 マテリアルサイエンス研究科 准教授 高村 由起子(内線:1570)


2015セミナー151104RT.pdf

×