Ab Initio Analysis of Structural, Magnetic, Electronic, and Optical Properties of Rare-Earth Orthoferrites RFeO₃ (R = Pr, La, Y)

We present a comprehensive theoretical investigation into the structural, elastic, magnetic, electronic, and optical properties of rare-earth orthoferrite perovskites RFeO₃, where R represents praseodymium (Pr), yttrium (Y) and lanthanum (La). The study employs density functional theory (DFT) calculations, implemented using the Vienna Ab initio Simulation Package (VASP). First, the mechanical stability and structural properties are calculated with generalized gradiant approximation/Perdew-Burke-Ernzerhof method. To achieve a more accurate description of the electronic, magnetic characteristics and for understanding the behavior of oxides four magnetic configurations (FM, A-AFM, C-AFM, and G-AFM) were considered and the Hubbard correction (GGA + U) was applied over the generalized gradient approximation. Our findings reveal that all three materials (YFeO₃, LaFeO₃, and PrFeO₃) exhibit semiconducting behavior, with a stable G-type antiferromagnetic ground state. The incorporation of the Hubbard U parameter in the calculations enhances the magnetic moment of the Fe atom and increases the bandgap value. In addition, the optical properties of systems are investigated and it is found that all three materials exhibit a strong absorption in the ultra-violet region. Within the 400–800 nm visible spectrum, all materials display relatively weak absorption, with LFO exhibiting the strongest absorption, followed by YFO and subsequently PFO.