https://doi.org/10.1140/epjb/e2006-00003-7
Thermal hysteresis of a simulated Al2O3 system
Dept. of Physics, College of Natural Sciences, HochiMinh City National University
227 Nguyen Van Cu Str., Distr. 5, HochiMinh City, Vietnam
Corresponding author: a vvhoang2002@yahoo.com
Received:
7
March
2005
Revised:
14
August
2005
Published online:
19
January
2006
Thermal hysteresis in a simulated Al2O3 system has been
investigated using a Molecular Dynamics (MD) method. Simulations were done
in the basic cube under periodic boundary conditions containing 3000 ions
with Born-Mayer type pair potentials. The system was cooled down from 7000 K
to 0 K and heated up from 0 K to 7000 K by the same cooling/heating rate of
K/s. The temperature dependence of the system density
upon cooling and heating shows thermal hysteresis. The differences between
structure and dynamics of the models obtained by cooling (MOBC) and heating
(MOBH) at three different temperatures of 2100 K, 3500 K and 5600 K have been
detected. Calculations show that the differences in the dynamics of the
systems are more pronounced than those in the structure. Furthermore,
dynamical heterogeneities in MOBC and MOBH at the temperature of 2100 K have
been studied through a non-Gaussian parameter and comparison of partial
radial distribution functions (PRDFs) for the 10% most mobile or immobile
particles with their corresponding mean ones. Cluster size distributions of
the 10% most mobile or immobile particles in MOBC and MOBH at the
temperature of 2100 K have been obtained. Calculations show that differences
in dynamical heterogeneities are pronounced.
PACS: 61.43.Fs – Glasses / 78.55.Qr – Amorphous materials; glasses and other disordered solids / 61.43.Bn – Structural modeling: serial-addition models, computer simulation
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006
