TY - JOUR
ID - 1677
TI - Theoretical study of ThO2 by first principles calculations
JO - Iranian Journal of Physics Research
JA - IJPR
LA - en
SN - 1682-6957
AU - Mahdavi, M
AU - Sahafi, M H
AD - Department of Physics, Faculty of Science, University of Mazandaran, Babolsar, Iran
Y1 - 2021
PY - 2021
VL - 21
IS - 1
SP - 91
EP - 109
KW - nuclear fuel
KW - Debye-Einstein thermal model
KW - vibrational entropy
KW - volumetric expansion ā€ˇcoefficient
DO - 10.47176/ijpr.21.1.41038
N2 - In this paper, the thermodynamic, structural properties and vibrational spectrum of thorium dioxide have been studied using the Density Functional Perturbation Theory (DFPT) and Density Functional Theory (DFT) in the framework of first principles calculations. Quantum espresso software, which is an open source computing code, has been used in order to compute the kohn-Sham equations to obtain the minimum total energy of crystal. The vibrational spectrum of the thorium dioxide was examined along various symmetrical directions, and the results showed the dynamical stability of the crystal system. The quasi-harmonic Debye-Einstein model as implemented in GIBBS2 Code was used to calculate the thermodynamic properties of thorium dioxide at high temperatures and pressures. The simulation results showed that the Debye temperature of thorium dioxide decreased with increasing temperature at a constant pressure and increased with increasing pressure at a constant temperature. Increasing the Debye temperature indicated an increase in the crystal stiffness and the average sound velocity. It was observed that the volumetric thermal expansion coefficient and gruneisen parameter decreased exponentially with increasing pressure at a constant temperature, while increased with increasing temperature at a constant pressure, indicating an increase in heat transfer in the crystal lattice
UR - https://ijpr.iut.ac.ir/article_1677.html
L1 - https://ijpr.iut.ac.ir/article_1677_e7e59b65a2ab3d1449ebdfdde7301b80.pdf
ER -