Study of structural, mechanical, thermodynamic, and optical properties of rare‑earth based perovskite oxides AcXO3 (X = Al, Ga, In)

The rare earth-based perovskite oxides are vastly studied for optoelectronic and photovoltaic
applications. Here in this manuscript, the structural, mechanical, thermodynamic,
electronic, and optical properties of AcXO3
(X = Al, Ga, In) are addressed by density functional
theory (DFT) based WIEN2k code. The optimized parameters are reported from the
Birch–Murnaghan equation of states in terms of lattice constant and bulk modulus. The
elastic constants C11,
C12,
and C44
for the cubic phase satisfy the Born–Huang stability conditions.
The Poisson and Pugh’s ratios discriminate that the Ac(Al/Ga)O3 have brittle and
AcInO3
ductile nature. The thermodynamic parameters like melting temperature, Debye
temperature, and lattice thermal conductivity have also been explained in terms of elastic
constants and moduli. The electronic behavior is explained by the band structures and density
of states which is mainly contributed by Ac-d, X-p, and O-p states. The replacement of
Al with Ga, and In reduces the bandgap from 4.1 to 2.2 eV. The optical characteristics are
studied in terms of dielectric constants, absorption coefficient, reflection, refractive index,
optical loss, and their dependent parameters. The absorption region shifts from ultraviolet
to the visible region making them significant for diverse optoelectronic applications.