Crystal structure determination by 3D electron diffraction


Event details

Date 19.05.2022 14:0015:30  
Speaker Dr. Lukas Palatinus, Czech Academy of Sciences
Location Online
Category Conferences - Seminars

3D electron diffraction (ED) is a crystallographic technique allowing structure analysis from single submicrometric crystals. This technique was born almost two decades ago, but it is now going through a phase of explosive development. Some eight years ago its general applicability and achievable accuracy was still a matter of debates. Five years ago, first reports showing reliable localization of hydrogen atoms by 3D ED appeared, and refinements with figures of merit approaching those of X-ray diffraction became possible. Today, observation of hydrogens and other structural details is considered routine, and advanced applications like charge density analysis from 3D ED data are emerging.
The webinar will give a brief overview of the development of the technique and then it will focus on the challenges technique poses from the experimental and data-processing point of view. An overview of applications will be given cover materials ranging from intermetallic alloys including precipitates through multiphasic mineralogical samples all the way to hydrated materials, MOFs and complex organic materials. The determination of absolute structure by electron crystallography will also be discussed. It will be shown that 3D ED is ripe enough to be immediately useful for material scientists and chemists who need crystallographic characterisation of microcrystalline materials, but it is also young enough to offer exciting opportunities for any material scientist wishing to contribute to its development. 

Lukas Palatinus studied mineralogy and geochemistry at the Charles University in Prague. During his PhD. At the University Bayreuth, Germany he focused on the crystallographic analysis of modulated structures. Later, during the post-doc stay at the EPFL, Lausanne, Switzerland, he developed the program Superflip for the solution of the crystallographic phase problem for periodic and aperiodic crystals, using iterative dual space algorithms. 
Since 2009, Dr. Palatinus is the head of the group of electron crystallography at the Institute of Physics of the Czech Academy of Sciences in Prague. He and his co-workers are developing methods for crystal structure analysis from electron diffraction data, with the main focus is on the structure refinement from 3D electron diffraction tomography data using the dynamical diffraction theory.