Predictions on structural, electronic, optical and thermal properties of lithium niobate via firstprinciple computations
Publication Type
Original research
Authors

In this work, we present our predictions on lithium niobate
LiNbO3 concerning its structural, electronics, thermal and
optical properties. These predictions are done by means of
first-principles calculations performed within the full
potential linearised augmented plane wave plus local
orbital (APW + lo) approach designed within the density
functional theory (DFT). The generalised gradient
approximation (GGA), to appraise the electron exchange–
correlation, parameterised by Perdew–Burke and Ernzerhof
is implemented. From our calculations, optimised results for
lattice parameters are obtained by optimising the volume
of the simulated hexagonal unit cell of lithium niobate. Our
computed results for structural parameters are consistent
with the data reported in the literature. On the other hand,
for the better description of the band structure/energy
band gap, calculations of the band structure are performed,
as well, at the level of GGA-mBJ with and without the
inclusion of spin–orbit coupling effect. Our calculations of
electronic band structure and density of states (DOS) show
that LiNbO3 is a direct and wide bandgap material as the
transition is found to be along (Γ-Γ) symmetry direction
with numerical value about 4.084 eV. However, no
significant influence of the spin–orbit coupling (SOC) is
noted on the band gap energy. Furthermore, optical
parameters like dielectric function, anisotropy, refractive
index, birefringence, extinction and absorption coefficients,
optical conductivity and the energy loss spectrum (EELS)
have also been calculated for an energy range, 0–40 eV.
Similarly, by employing the ‘Debye Quasi-Harmonic Model’
crucial thermal parameters of the LiNbO3 are predicted.

Journal
Title
PHILOSOPHICAL MAGAZINE
Publisher
Taylor and Francis
Publisher Country
United Kingdom
Indexing
Thomson Reuters
Impact Factor
1.855
Publication Type
Online only
Volume
--
Year
2020
Pages
23