Dr. Cheng Wang [from Lawrence Berkeley National Lab]

Title: Resonant Soft X-ray Scattering for Material Science

Time: 10:00 - 11:00, November 10

Place: Conference Room 201, Building 6, HPSTAR (Shanghai)

Host: Bin Chen

Abstract:

To meet the challenge on investigating new and complex materialsthat is relevant to mesoscale energy science, it is essential to connectmicroscopic dynamical processes to activated kinetic processes and macroscopicfunction in diverse soft and hard materials. We need sharper tools in order todiscover, understand, and control mesoscale phenomena and architectures. Overthe past a few years, we have developed Resonant Soft X-ray Scattering (RSoXS)and constructed the first dedicated resonant soft x-ray scattering beamline atthe Advanced Light Source, LBNL. RSoXS combines soft x-ray spectroscopy withx-ray scattering thus offers statistical information for 3D chemical morphologyover a large length scale range from nanometers to micrometers. Using RSoXS tocharacterize multi-length scale materials with heterogeous chemical structures,we have demonstrated that soft x-ray scattering is a unique complementarytechnique to conventional hard x-ray and neutron scattering. Its uniquechemical sensitivity, large accessible size scale, molecular bond orientationsensitivity with polarized x-rays and high coherence have shown great potentialfor chemical/morphological structure characterization for many classes ofmaterials. Some recent development of in-situ soft x-ray scattering within-vacuum sample environment will be discussed. In order to study sciences innaturally occurring conditions, we need to overcome the sample limitations set bythe low penetration depth of soft x-rays and requirement of high vacuum.Adapting to the evolving environmental cell designs utilized increasingly inthe Electron Microscopy community, customized designed liquid/gas environmentalcells will enable soft x-ray scattering experiments on biological,electro-chemical, self-assembly, and hierarchical functional systems in bothstatic and dynamic fashion. Recent RSoXS results on organic electronics, blockcopolymer thin films, and membrane structure will be presented.

Biography of the Speaker:

王诚，美国Lawrence Berkeley National Lab研究员。2002年7月毕业于吉林大学物理系，获得学士学位。本科毕业后留学美国北卡罗来纳州立大学，师从 Harald Ade教授从事同步辐射软X射线的研究，2008年1月获博士学位。博士毕业后在劳伦斯伯克利国家实验室的先进光源 (Advanced Light Source)从事软X光散射的博士后研究。2011年3月被聘为研究员。研究工作主要致力于开发和利用各种先进的软X光技术，将X光显微学，散射学，及光谱学相结合，用来研究介观尺度下物理，化学现象，从多维角度解决凝聚态物理和软材料科学中，尤其是在能源科学应用中一些前沿问题。