2006/10/14 by Magnus Bergroth, Bergroth, Magnus N. J., Sharon C. Glotzer +1
Materials Science · Physics and Astronomy · #Material Dynamics and Properties #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.cond-mat/0610395
By molecular dynamics (MD) simulation of the one-component Dzugutov liquid in\na metastable equilibrium supercooled state approaching the glass transition, we\ninvestigate the structural properties of highly mobile particles moving in\nstrings at low temperature T where string-like particle motion (SLM) is well\ndeveloped. We find that SLM occurs most frequently in the boundary regions\nbetween clusters of icosahedrally-ordered particles and disordered,\nliquid-like, domains. Further, we find that the onset T for significant SLM\ncoincides with the T at which clusters of icosahedrally-ordered particles begin\nto appear in considerable amounts, which in turn coincides with the onset T for\nnon-Arrhenius dynamics. We find a unique structural environment for strings\nthat is different from the structure of the bulk liquid at any T. This unique\nstring environment persists from the melting T upon cooling to the lowest T\nstudied in the vicinity of the mode-coupling temperature, and is explained by\nthe existence of rigid elongated cages. We also form a criterion based solely\non structural features of the local environment that allow the identification\nof particles with an increased propensity for mobility.\n