Colloquium- “Diffraction Studies of Materials Properties using Large Scale X-ray and Neutron Facilities” with Dr. Stephan O. Hruszkewycz and Dr. Stephan Rosenkranz (Argonne National Laboratory)
Colloquium
December 4, 2024
3:00 PM - 4:00 PM
Location
2SES 238
Calendar
Download iCal FileDiffraction Studies of Materials Properties using Large Scale X-ray and Neutron Facilities
Stephan Hruszkewycz and Stephan Rosenkranz
Materials Science Division, Argonne National Laboratory, Lemont, IL 60439 USA.
The atomic scale arrangement of atoms, ions, and spins in crystalline materials underlies their wide range of properties of importance everywhere from large structures (buildings, bridges, ships), machines that can operate under extreme conditions (engines, rockets, power plants) to highly efficient miniature devices that power everyday electronics. Standard diffraction techniques, based on Bragg’s Law, probe the long-range crystalline order that has provided the traditional basis to explain the structure-property relationships of materials. However, it is now well established that evey within bulk materials, local disorder and nanoscale correlations embedded within a long-range ordered crystalline structure often lead to strongly enhanced responses to external stimuli (such as magnetic or electrical field) or novel, emergent phenomena, with properties desirable for future applications. Similarly, nanocrystals and epitaxial thin films can contain internal structural heterogeneities not present in their bulk counterparts and a high surface to volume ratios that also offer yet more degrees of control of novel properties.
Resolving such nanoscale correlations is not possible with traditional laboratory-based diffraction techniques and requires novel methods and instrumentation at large scale synchrotron X-ray and neutron scattering facilities. Understanding of such systems with long- and short-range correlations in both bulk and nanoscale crystals generally requires advanced analysis and the development of novel characterization method development. In the Materials Science Division at Argonne National Laboratory there are two groups developing and utilizing such novel methods and working in collaboration with other groups with expertise in sample synthesis, mathematical and computational methods, and theory to obtain insight into novel quantum and energy materials.
The neutron and x-ray scattering group (led by Stephan Rosenkranz) has recently advanced methods to efficiently collect scattering intensities from single crystals over large volumes of reciprocal space from facilities such as the Spallation Neutron Source (Oak Ridge National Laboratory) and the Advanced Photon Source (APS) (Argonne) and obtain insight into local correlations in real space through three-dimensional Fourier transforms and by applying Machine Learning methods. Combined with inelastic neutron scattering, we obtain detailed insight into ionic, electronic, and spin correlations and how they related to fast solid-state ionic transport, metal-insulator and multiferroic transitions, superconductivity, and spin-liquid and spin glass behavior in geometrically frustrated magnets. The coherent and ultrafast x-ray science (led by Stephan Hruszkewycz) has a focus on developing new imaging methods that exploit the greatly enhanced x-ray coherence of the newly upgraded APS and free electron laser user facilities such as the LCLS that enable nanoscale resolution and real-time access to fundamental processes in materials. We have recently shed new light on phase transitions in hydrogen storage materials and domain reconfiguration dynamics in ferroelectric and charge density wave materials under optical and electronic excitations. An overview of the research portfolio of these two groups will be presented as well as introductions to the features of large-scale DOE User Facilities that we exploit for materials science in our programs.
This work is supported by the U.S Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division
Date posted
Nov 18, 2024
Date updated
Nov 27, 2024