Dr. Rui Li [IHEP, China]

Title: Pressure-induced Changes In The Electron Density Distribution In Ge Near The α-β Phase Transition

Time: 10:00 - 11:00 AM, Tuesday, June 14, 2016

Place: Conference Room C206, HPSTAR (Beijing)

Host: Dr. Yang Ding

Abstract:

High pressure single crystal diffraction is an emerging high pressure technique, which can be used to study materials with complex structures, and to obtain high precision and detail crystallographic data. In this talk, I will present the development of high pressure single crystal diffraction technique, which is described based on experiments using synchrotron radiation and diamond anvil cell (DAC) technologies; a set of data collection procedures has been established for high pressure single crystal diffraction at high pressure stations at the Beijing Synchrotron Radiation Facility (BSRF) and the Advanced Photon Source (APS); a variety of single crystal data processing methods have been tested for optimal solutions considering the actual problems of the high pressure device, resulting in new data processing procedures that are optimized and integrated for high pressure single crystal diffraction. By applying the established approach, single crystal Ge samples have been studied for high pressure structural evolution including the pressure dependence of the electron density distribution (EDD), which provides information for understanding the mechanism of the high pressure phase transition. Based on the single crystal diffraction technique and data processing procedures, the high multigrain diffraction method has also been developed.

Biography of the Speaker:

Dr. Rui Li received her Ph.D. in Condensed Matter Physics from the Institute of High Energy Physics at the Chinese Academy of Science. During Oct. 2013-Sep. 2015, Dr. Li as a predoctoral associate worked at the High Pressure Collaborative Access Team (HPCAT) in Argonne National Laboratory; previously, she worked at the Beijing Synchrotron Radiation Facility. Her research mainly focused on the approach in developing high-pressure single crystal x-ray diffraction (SC-XRD) techniques and the electronic origin of the structural phase transitions in the group IV elements with the established SC-XRD techniques. Through the years she has also worked on many other synchrotron spectroscopy techniques, Raman scattering, infrared reflectivity spectroscopy and resistance measurement, where some of the works are continuing.