Coherent X-ray Diffraction Imaging at Nanoscale - Ivan Vartaniants
Channel: LINXS
Date: 04/11/2022

Abstract: 
Coherent X-ray Diffractive Imaging (CXDI) is a modern technique that utilizes comparably large coherence properties of the X-ray beams generated by the modern X-ray synchrotron sources. In my talk I will be focused on two specific cases. First, I will discuss reconstruction of small grains of colloidal and mesoscopic crystals. In this case position of each particle in the grain was found to be located better than 9 nm. Next, I will discuss in-situ CXDI experiments performed in Bragg geometry for single nano-particles under catalytic reaction conditions. Here, I will focus on the strain values determined on the surface of the particle for different facets.

Bio: 
Ivan Vartaniants received his PhD in Theoretical and Mathematical Physics from Moscow Engineering Physical Institute (MEPhI) in 1984. He was a leading research scientist at the Institute of Crystallography of the Russian Academy of Sciences and visiting research scientist at the Max-Planck-Institutes for Solid State Research and Metal Research in Stuttgart, and at the University of Illinois at Urbana-Champaign, where he took up a position of visiting Research Associate Professor in 2001-2004. Since 2004 he is a senior scientist and a group leader and at Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany and since 2011 Professor (part time) of Physics at National Research Nuclear University, MEPhI, Moscow, Russia. His present research interests are in the field of applications and theory of coherent x-ray scattering and high resolution coherent x-ray imaging. His special interest lies in time resolved studies with novel free-electron lasers such as FLASH and LCLS.He is an author/co-author of over 170 publications in peer reviewed journals and he is presently a co-editor of Acta Crystallographica A journal. He was for six years a member of Scientific Advisory Committee (SAC) of the MAX IV synchrotron radiation facility in Lund, Sweden, and member of the Proposal Review Panel (PRP) of the free-electron laser FERMI in Trieste, Italy, he is also a member of the International Scientific Advisory Committees of the conference series "X-TOP".