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. [ABSTRACT FROM AUTHOR]