学术报告:Scanning Transmission X-ray Microscopy (STXM) at the Canadian Light Source

题 目:Scanning Transmission X-ray Microscopy (STXM) at the Canadian Light Source

报告人:Dr. Jian Wang, SM Beamline, Canadian Light Source, University of Saskatchewan

时 间:2012年6月20日(星期三)上午9:30

地 点:张江园区办公楼109会议室

报告简介:
The scanning transmission X-ray microscope (STXM) at the Canadian Light Source (CLS) (covering 130 - 2500 eV) images the structure, quantitative distributions (maps) of chemical components, molecular orientation, as well as obtains the XANES spectroscopy for a wide range of samples from the fields of materials sciences, life sciences and environmental and earth sciences, at high spatial resolution (~30 nm) and high energy resolution (~0.05 eV), and with experimental environments ranging from ambient, controlled in situ (wet, humidity, temperature), high vacuum, and magnetic fields. In addition, the STXM based spectrotomography was recently developed to enable morphological visualization and quantitative chemical imaging in 3D.

In this talk the principles, experimental details, data acquisition and analysis of 2D and 3D STXM will be discussed. Selected examples will be presented including 2D STXM, also with polarization dependence such as X-ray linear dichroism (XLD), and X-ray magnetic circular dichroism (XMCD), for carbon nanotube, graphene and magnetic nanomaterials, and 3D STXM for biological unicellular microorganisms. Furthermore, recent STXM instrumentation developments such as total electron yield (TEY) detection for surface sensitivity and opaque samples, low energy X-ray fluorescence (LEXRF) detection for lowered detection limits, and coherent diffractive imaging (CDI), i.e. ptychography, will be briefly discussed. These examples and techniques intend to demonstrate a broad range of research options available to users by using the state-of-the-art facility of CLS STXM.