Special Seminar: Tuning Order in Disordered Materials

Jun Ding, Postdoctoral Fellow, Lawrence Berkeley National Laboratory

Friday, March 4, 2016, 3:30–4:30pm

Room 200, Cummings Hall

The structure-property relationships in materials play a key role in guiding the discovery and design of new materials with unique combinations of properties. However, a large number of materials are categorized by disorder, which is challenging to characterize. Thus the establishment of their structure-property relationships lags far behind that of structurally ordered crystalline materials. This talk will present results of computational modeling focused on two class of disordered structural alloys: metallic glasses and high-entropy alloys. Their unique internal structure presents new opportunities for design of high-performance materials for applications requiring mechanical, functional and irradiation-resistant behavior. The topological order and chemical order among these disordered structural alloys are investigated by atomistic simulations. It will be specifically shown that the local structural feature of metallic glasses are characterized by icosahedral order (containing twelve five-fold symmetry) at short-to-medium-range scale; the nature and extend of this order is shown to strongly correlate with various properties, including mechanical deformation, atomic vibration, and structural relaxation. Our findings pave a way toward concrete understanding and accelerated materials design of disordered structural alloys from the perspective of local structure. Finally, I will propose an outlook of future research by extending the computational framework to study novel energy-related disordered materials, with emphasis on tuning/optimizing internal structure for targeted energy applications.

About the Speaker

Dr. Jun Ding is currently a Postdoctoral Fellow at the Materials Science Division of Lawrence Berkeley National Laboratory and UC Berkeley, working with Prof. Mark Asta and Prof. Robert Ritchie. He graduated with BS degree from Shanghai Jiao Tong University (2010), and PhD degree from Johns Hopkins University (2014, with Prof. En Ma), both in materials science and engineering. Dr. Ding’s research is focused in the computational materials science, broadly spanned the areas of glassy materials, advanced structural alloys, supercooled liquids, lithium-ion batteries, phase transition and twin grain boundary. He has received a number of awards and fellowships including the Acta Student Award. 

For more information, contact Jessica Widdicombe at jessica.c.widdicombe@dartmouth.edu.