American University of Beirut
Physics Department
Invites you to a talk entitled
Direct Molecular Dynamics Simulations of Piezoelectric
and Piezothermal Couplings in Crystals
By
Dr. Wassim Kassim
Ecole Centrale Paris «Sciences pour l'ingenieur», FRANCE
Abstract
Molecular dynamics simulations are a great tool for the computationalist working as an
experimentalist. They offer the ability to probe the thermal and mechanical properties of materials
from the bulk down to the nanoscale, They provide atomic level information from the picosecond up
to the nanosecond. Here we present results on the piezoelectric and thermal properties of bulk and
superlattice forms of different piezocrystals (ZnO, AlN, SiO2) obtained using MD. We show the effect
of strain and piezo-stress on the intrinsic thermal conductivity of bulk crystals to be small but present
due to the modification of the phonon-mode properties. We also show the effect of local stress on
the thermal conductance of two different piezoelectric superlattices to be more significant, the
modification is theorized to be due to the local scattering of phonons at the interface although no
proof is yet to be offered. Nevertheless, the results of the SiO2 superlattice, we believe, are
encouraging enough to suggest experimental investigation, and can help with the development of
new nanoscale thermal solution devices.
Date: Monday, October 19, 2015
Time: 5:00 p.m.
Place: Emile Bustani for Physics, Rm. 333