Ansell Lecture Seminar Series – Dr. Paul Voyles

Frontiers in Glassy Materials:
Spatial and Temporal Complexity at the Nanoscale

Paul Voyles is Professor of Materials Science and Engineering and Harvey D. Spangler Professor of Engineering at the University of Wisconsin-Madison. He earned degrees in physics from Oberlin College and the University of Illinois, Urbana-Champaign, then worked as a post-doctoral member of technical staff at Bell Labs in Murray Hill NJ. He joined the UW-Madison in 2002 as an Assistant Professor. His research specialty is the structure of materials, investigated primarily with electron microscopy, supplemented by simulations and data science. He has worked on metallic and other glasses and on materials for microelectronics, spintronics, and superconductors. He was Chair of the Materials
Science and Engineering Department from 2016 to 2018 is currently director of the NSF-funded Wisconsin Materials Research Science and Engineering Center. He has published over 220 journal articles, book chapters, and conference proceedings.

Much of our day to day lives is spent interacting with some form of glassy material: looking through a silicate glass windshield while driving, drinking from a polyethylene glass bottle, or watching a display powered by organic glass light emitting diodes. However, the ubiquity and apparent featurelessness of glasses masks deep complexity associated with structural disorder, cooperative, spatially non-uniform atomic motions, and metastable thermodynamics. This talk will provide an introduction to the thermodynamics, kinetics, and structures common to
the glassy state of materials, and then present highlights of recent glass research in the Voyles group and the Wisconsin Materials Research Science and Engineering Center. These highlights include: (1) Surface diffusion on glasses that can be 108 times faster than bulk diffusion at the same temperature. (2) Use of surface to grow glass thin films more stable than natural ambers aged for thousands of years and glasses with quenched-in liquid-crystal order. (3) The first real-space images of nanometer-scale spatially heterogeneous dynamics near the glass transition
temperature. (4) Decoupling of atomic mobilities for different elements in a multicomponent liquid experimentally measured at deep undercooling. Many of these advances are made possible by advanced instrumentation for time-resolved electron nanodiffraction and four-dimensional scanning transmission electron microscopy.