Dynamics of Energy Materials Probed by Quasielastic Neutron Scattering

This event is sponsored by FAMU-FSU College of Engineering and Department of Chemical & Biomedical Engineering.

Abstract: A fundamental understanding of diffusion mechanisms and the factors influencing dynamics within energy materials is critical for designing and synthesizing new materials with enhanced properties and improved performance. Quasielastic neutron scattering (QENS) predominantly depends on the incoherent scattering cross-section of atoms and probes single-particle dynamics, thereby providing the self-diffusion coefficients of mobile species. Since hydrogen has the highest incoherent neutron scattering cross-section among all elements, this technique is particularly sensitive to hydrogen and is often used to explore the dynamics of hydrogen-bearing species. In the absence of hydrogen, depending on the scattering cross-section, QENS probes either single-particle or collective motion of atoms, such as lithium (incoherent) and sodium (coherent) ions, respectively. The use of QENS, together with inelastic neutron scattering and electrochemical measurements, to investigate the dynamics of various energy material systems—such as confined water and ionic liquids, as well as polymer and solid-state electrolytes—will be discussed.

Naresh C. Osti

Basis R&D Staff/Beamline Scientist

ORNL Neutron Scattering Division 

Speaker Bio: Naresh C. Osti received his MS in Physical Chemistry from Tribhuvan University, Kathmandu, Nepal. He obtained his PhD in Chemistry from Clemson University in South Carolina in 2014. He joined Oak Ridge National Laboratory (ORNL) as a postdoctoral researcher and worked under the supervision of Dr. Eugene Mamontov until 2017. He is currently an R&D Staff/beamline scientist at BASIS within the Neutron Scattering Division at ORNL. His research focuses on exploring the structure and dynamics of energy-related materials (hard and soft) to relate their structure-property relationship to their real-life application, especially of the nano-confined fluids, polymers, and polymer nanocomposites. He has extensively used different neutron scattering techniques at various user facilities (ORNL, Lujan Center at LANSCE, NIST-NCNR and ISIS) for materials characterization.