Publication Date
9-21-2018
Department
Ames Laboratory; Physics and Astronomy
Campus Units
Ames Laboratory, Physics and Astronomy
OSTI ID+
1478229
Report Number
IS-J 9788
DOI
10.1021/acs.jpclett.8b02629
Journal Title
Journal of Physical Chemistry Letters
Volume Number
9
Issue Number
19
First Page
5877
Last Page
5883
Abstract
In glassy materials, the Johari–Goldstein secondary (β) relaxation is crucial to many properties as it is directly related to local atomic motions. However, a long-standing puzzle remains elusive: why some glasses exhibit β relaxations as pronounced peaks while others present as unobvious excess wings? Using microsecond atomistic simulation of two model metallic glasses (MGs), we demonstrate that such a difference is associated with the number of string-like collective atomic jumps. Relative to that of excess wings, we find that MGs having pronounced β relaxations contain larger numbers of such jumps. Structurally, they are promoted by the higher tendency of cage-breaking events of their neighbors. Our results provide atomistic insights for different signatures of the β relaxation that could be helpful for understanding the low-temperature dynamics and properties of MGs.
DOE Contract Number(s)
AC02-07CH11358
Language
en
Department of Energy Subject Categories
36 MATERIALS SCIENCE
Publisher
Iowa State University Digital Repository, Ames IA (United States)
