Research Article
First-Principles Calculations to Investigate Structural, Electronic,
Optical, and Elastic Properties of Ceria
Lemessa Asefa Eressa
1
and Teshome Gerbaba Edossa
2
1
Department of Physics, College of Natural & Computational Sciences, Ambo University, Ambo, Ethiopia
2
Departments of Physics, College of Natural & Computational Sciences, Wachemo University, Hossana, Ethiopia
Correspondence should be addressed to Lemessa Asefa Eressa; lemessaphys@gmail.com
Received 16 January 2022; Accepted 25 April 2022; Published 3 June 2022
Academic Editor: Raouf El Mallawany
Copyright © 2022 Lemessa Asefa Eressa and Teshome Gerbaba Edossa. is is an open access article distributed under the Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
e structural, electronic, optical, and elastic properties of Ceria (CeO
2
) were investigated using local density approximation
(LDA), PBE, DFT + U, and PBE0 approximations. In all approximations, the convergence test of total energy with respect to
kinetic energy cutoff, k-point, and lattice constant of CeO
2
was performed consequently to increase the accuracy of computations.
e O (2p)-Ce (4f) bandgap of CeO
2
calculated using DFT + U (3.0 eV) is consistent with experimentally reported value
(3.0–3.33 eV) than with LDA (2.2 eV), PBE (2.5 eV), and PBE0 (4.47 eV). Both LDA and PBE underestimated the bandgap of CeO
2
while the PBE0 overestimated the bandgap of CeO
2
as compared to the experimental value. e optical properties such as the
imaginary part of the dielectric function (ε
2
), extinction coefficient (k), and refractive index (n) of ceria obtained using the three
approaches are also consistent with the available theoretical and experimental data. In addition, the maximum peak for absorption
coefficient was found at about 13 eV for (LDA and PBE) and around 11 eV for DFT + U calculations. Furthermore, the analyses of
optical properties support the electronic properties of ceria. e elastic properties such as bulk modulus, shear modulus, Young’s
modulus, Poisson’s ratio, Debye temperature, and Debye sound velocity were computed to investigate the mechanical properties
of CeO
2
and compared with the experimental and theoretical results. e result of elastic parameters found confirms that CeO
2
is
mechanically stable and has potential for a variety of different electronic applications.
1. Introduction
Ceria (CeO
2
) is a technologically significant oxide material
that has a wide range of applications. It is widely used in
automotive three-way catalysts (TWCs) to remove NOx and
CO [1], in luminescence devices, gas sensors, and high-
temperature superconducting tapes [2], as a catalyst in fuel
cells [3–5]. Ceria is a highly correlated material, due to the
fact of their confined d- and f-orbitals, where Coulomb
repulsion energy acts on them on the order of the electronic
bandwidth [1, 6]. Only a few researches have been carried
out with density functional theories to define the needed
properties of CeO
2
. erefore, it is important to investigate
the properties of ceria for the advancement of their practical
applications with different density functional theories.
e local density approximation (LDA) or PBE under-
estimates and fails to reproduce the correct electronic
properties (bandgap) of CeO
2
due to the f-electron delo-
calization associated with the self-interaction problem [7].
However, the electronic structure of CeO
2
is fundamental to
understanding the effects of ions, doping, and other prop-
erties that are prerequisites to using CeO
2
for different
technological applications. Hence, in order to account for the
strong on-site Coulomb repulsion among the Ce-4f electrons,
a Hubbard parameter U is added (DFT + U approach) so as to
get better electronic properties. e objective of this study was
to investigate the structural, electronic, optical, and me-
chanical properties of CeO
2
using density functional theories.
e values obtained were compared with the available the-
oretical and experimental data.
Hindawi
Advances in Condensed Matter Physics
Volume 2022, Article ID 3619600, 11 pages
https://doi.org/10.1155/2022/3619600