MSE Colloquium: Takeshi Egami, Atoms have feelings, too: How they suffer and get frustrated in liquids and solids

UT-ORNL Distinguished Scientist/Professor, Joint Institute for Neutron Sciences Director Emeritus

Abstract

Once Sir Alan Cottrell remarked, “just like people defects make materials interesting”.  Indeed a perfect crystal, such as a diamond, is functionally boring.  We are going after more and more complex materials with remarkable functionality.  Complex materials are characterized by the diversity of the atomic environment, deviations from perfect uniformity.  The extreme cases of such diversity are liquids and glasses where every atom has a distinct environment, just like we do.  Some time ago I introduced a concept of the “atomic-level stresses” by extending the idea of stress and strain down to the atomic level.  This idea revealed how much atoms are suffering and get frustrated in liquids, glasses, crystals with defects, and even compounds, because the atoms do not nicely fit to the environment they are placed in.  This concept led to deeper insights and better understandings of the behavior of complex matter including liquids and glasses.  I discuss how this approach can benefit the study of complex matter in general, including high-entropy alloys and other complex materials.  Atoms are lovable, after all, if you have enough empathy.

Bio

 

Dr. Takeshi Egami received his Bachelor's degree in Applied Physics from the University of Tokyo in 1968, and his Ph.D. in Materials Science from the University of Pennsylvania in 1971.  After the postdoctoral research at the University of Sussex, U.K. and Max-Planck-Institute in Stuttgart, Germany, he returned to the University of Pennsylvania in 1973 as Assistant Professor. He was promoted to Associate Professor in 1976, to Professor in 1980, and was the Chair of the Department of Materials Science and Engineering (1997 to 2002). In 2003 he moved to the University of Tennessee as UT-ORNL Distinguished Scientist/Professor at Department of Materials Science and Engineering and Department of Physics and Astronomy, with join appointment at Materials Science and Technology Division, Oak Ridge National Laboratory. He was Director of UT-ORNL Joint Institute for Neutron Sciences (JINS) (2008-2015). He is known for promoting the use of the PDF technique to the study of complex crystalline materials and developing a theory of liquids and glasses based upon the concept of the atomic-level stresses. He received 2010 J. D. Hanawalt Award from International Center for Diffraction Data, 2003 B. E. Warren Award for Diffraction Physics from American Crystallography Association, Metal Physics Achievement Award from Japan Institute of Metals (1988), Robert Lansing Hardy Gold Medal from TMS-AIME (1974), and other awards. He is Fellow of the American Physical Society. Dr. Egami has published 1 book, 25 full reviews and over 530 technical papers.  He gave over 320 invited technical presentations at national and international conferences, in addition to numerous seminars.