Program

O.19 -- Oral, NCTP-41

Date: Wednesday, 3 August 2016

Time: 14h00 - 14h20

Dynamical heterogeneity in supercooled liquid and glassy states of simple system

Nguyen Hoang Giang (1), Vo Van Hoang (1), Dang Minh Tan (2)

(1) Institute of Technology, Vietnam National University - Ho Chi Minh City (2) Department of Physics, College of Natural Sciences, Can Tho University

We present molecular dynamics (MD) simulations of dynamical heterogeneity in 3D simple monatomic supercooled liquid and glassy states obtained by cooling from liquid to glassy state. Models contain 8000 particles interacted via Lennard-Jones-Gauss potential. Evolution of structure and various thermodynamic properties upon cooling from liquid to glassy state is analyzed in details via radial distribution function (RDF), temperature dependence of total energy, mass density, time – temperature dependence of mean - squared displacement (MSD), temperature dependence of fraction of atoms with diffferent mobilities, size of the largest cluster and mean cluster size of atoms, fraction of solidlike atoms, 3D visualization of atomic configurations. Via intensive MD simulation of glass formation in 3D simple supercooled liquids we find that atoms with the same or close mobilities have a tendency to aggregate into clusters. With decreasing temperature, fraction of these atoms passes over a maximum and then it decreases downto zero. In contrast, fraction of solidlike atoms (i.e. with the slowest mobility) increases monotonously with a sudden increase in the vicinity of glass transition reaching almost 100% at low temperature to form a solid glassy state. The size of the largest cluster of atoms with different mobilities also has the same tendency. It is quite new for glass formation in 3D simple system. On the other hand, we also find that glass formation in 3D supercooled monatomic liquids is homogeneous. Acknowledgements: This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant 103.01-2014.86.

Presenter: Nguyen Hoang Giang