Geology Seminar Series - Dr. Ning Chen: X-ray absorption spectroscopy: a molecular scale approach in geological and environmental sciences

Wed., Mar. 17, 2021 4:00 p.m.

Location: https://uregina-ca.zoom.us/j/92337163072?pwd=b2xnMFpVYXRUQnlRYnZaWEF2WDlnUT09

Title: X-ray absorption spectroscopy: a molecular scale approach in geological and environmental sciences

Speaker: Dr. Ning Chen, Canadian Light Source

Abstract:

The Canadian Light Source (CLS) is Canada’s national and international centre for synchrotron science and its applications. CLS is a third-generation synchrotron providing synchrotron radiation from 0.62 meV in the far- infrared to 100 keV hard X-rays with 23 beamlines operational, providing research capabilities in material science, physics, chemistry, biological sciences, protein crystallography, medical and life sciences, environmental science, and geological sciences.

As one of the most extensively applied synchrotron techniques, X-ray absorption spectroscopy (XAS) plays its unique role in research of geological and environmental sciences. Its Nano to sub Nano scale element specific local structure probing capability has a resolution of ~0.02Å in scale for the first shell and further outer shell coordination featured by samples’ bulk, shell-by-shell, bond-by-bond, site-by-site structure and chemistry, making a molecular level understanding possible for both crystalline and amorphous systems. This presentation would like to introduce CLS to researchers at the Department of Geology, University of Regina, focusing on X-ray absorption spectroscopy (XAS) technology, XAS capabilities at Hard X-ray MicroAnalysis (HXMA) beamline at CLS, and the full-scale user support at HXMA beamline. The XAS element specific local structural characterization will be discussed throughout case study from first shell local structural probing of shell-by-shell and bond-by-bond characterization, transition elements position transferring within structure framework of crystalline material, single atom catalyst characterization, to Nano to sub Nano scale characterization of developing/dissolving dynamic process of a spinel type LiMn₂O₄particles during energy storage and releasing process,andchromiteparticle size estimation for an environmental biochar sample system.