Electronic, optical, magnetocaloric, and thermoelectric properties of La0.5Sm0.2Sr0.3MnO3: a first-principles DFT-MFT investigation

Abstract

Density functional theory (DFT + U) and mean-field theory (MFT) calculations were carried out on La₀.₅Sm₀.₂Sr₀.₃MnO₃ to investigate its electronic, magnetic, and optical properties using the Wien2k package. The total density of states and band structure indicate a semi-metallic ferromagnetic nature. Magnetic properties analyzed with MFT reproduced magnetization isotherms and magnetic entropy (−ΔS) curves, consistent with ferromagnetic behavior. The good agreement between experiment and simulation highlights the reliability of the employed model in predicting the magnetocaloric properties of La₀.₅Sm₀.₂Sr₀.₃MnO₃. Optical parameters, including dielectric constants ε₁(ω) and ε₂(ω), absorption coefficient α(ω), and optical conductivity, were studied over 0–14 eV. The Seebeck coefficient (S) decreases with temperature, and its positive sign confirms hole conduction. The figure of merit attains a maximum ZT = 1.22 at 200 K.