Title: X-ray Diffraction in the Nanoscale

Date: Friday, December 23

Time: 15:00 – 16:00

Place: Science 103

Abstract

X-ray diffraction (XRD) is a widely-used, non-destructive and high-resolution technique to characterize atomic configurations in crystalline materials. For the past decades, XRD has been used to analyze nanocrystalline materials which possess a novel and a very particular form of crystallinity. In this talk, I will explain how standard methodologies to process x-ray diffraction data from nanocrystalline powders fail to accurately characterize such materials. Starting from the fundamental theory of diffraction for regular crystals, I will point out which parts of the classical theory is incompatible with the current atomistic models we have for nanocrystals. Then I will demonstrate how these incompatibilities propagate during diffraction analysis of small nanocrystals and how much uncertainty they introduce to the resulting characteristics derived from diffraction data. I will conclude my discussion by suggesting ways to minimize these uncertainties and not to deceive ourselves with diffraction data.

Biography:

Dr. Hande Öztürk is an expert on high-resolution characterization of materials with X-ray diffraction. She received her PhD in 2015 from Columbia University Department of Applied Physics and Applied Mathematics. From 2016 to 2018 she worked as a postdoctoral research scientist in the National Synchrotron Light Source II at the Brookhaven National Laboratory, USA. There she participated in the development of the Hard X-ray Nanoprobe which is a novel, sub-Angstrom resolution X-ray microscope capable of high-resolution characterization and imaging of ultrasmall nanomaterial samples and isolated nanostructures.

Dr. Öztürk joined Özyegin University in August 2018 and she has been working as an Assistant professor of Materials Science. Since returning to Turkey, Dr. Öztürk has been working on the development of a new theory of x-ray diffraction compatible with characteristics of nanomaterials. Her research has been supported by Tubitak with the 2232 International Fellowship of Outstanding Researchers and 3501 Career Development Program.