Ab-initio prediction of structure stability, electromagnetic, optical and thermoelectric behavior of orthorhombic LaXO3 (X= Cr, Mn, Fe): For device application

Consequences of Tuning Rare-Earth RE3+-Site and Exchange-Correlation Energy U on the Optoelectronic, Mechanical, and Thermoelectronic Properties of Cubic Manganite Perovskites REMnO3 for Spintronics and Optoelectronics Applications

Both rare-earth SmMnO₃ and EuMnO₃ compounds that belong to transition-metal-based manganite perovskites REMnO₃ have been studied deeply in this paper. The structural, elastic, optoelectronic, magnetic, mechanical, and thermoelectronic properties of cubic SmMnO₃ and EuMnO₃ compounds have been computed using the full-potential linearized augmented plane-wave (FP-APLW) method in the frame of density functional theory (DFT). To compute the ground-state energy, the effect of exchange-correlation potential was treated via the application of generalized gradient approximation within Perdew, Burke, and Ernzerhof (PBE-GGA) plus its corrected method (GGA + U). The spin-polarized results of band structures, density of states (DOS), and magnetic moments show that SmMnO₃ and EuMnO₃ have ferromagnetic half-metallic (FM-HM) behavior. Optical responses of dielectric function (ε(ω)) are explained by computing the real ε₁(ω) and imaginary ε₂(ω) parts of ε(ω), refractive index n(ω), extinction coefficient k(ω), absorption coefficient α(ω), optical conductivity σ(ω), reflectivity R(ω), and energy loss function L(ω) using GGA and GGA + U. Also, we computed and discussed the thermoelectronic properties of SmMnO₃ and EuMnO₃, including Seebeck coefficient (S), holes and electrons charge carrier concentration (n), electrical conductivity (σ/τ), power factor (S ²σ/τ), figure of merit (ZT), thermal conductivity (κ), and specific heat capacity (C _V), as a function of temperature (T), using GGA and GGA + U methods based on BoltzTrap scheme. The present results confirm the perfect mechanical and thermal stability of two perovskites which make SmMnO₃ and EuMnO₃ promising materials for spintronics, optoelectronics, high-temperature, and other related applications.