Study of structural, electronic, magnetic, and optical properties of A2FeMnO6 (A = Ba, La) double perovskites, experimental and DFT analysis

The electronic, magnetic, dielectric, and optical properties of double oxide perovskites A2FeMnO6 (A= Ba, La) are studied for spintronic and energy applications by experimental and theoretical routes. The hydrothermal process is used for sample preparation and modified Becke and Johnson potential through Wien2K code for simulation. The XRD and Rietveld refinement patterns confirm the cubic structure of Ba2FeMnO6 with space group Fm3m (No.225) and orthorhombic structure of La2FeMnO6 with space group Pbnm (No. 62). The SEM analysis of surface morphology shows particle size on average between 500 and 550 nm. The FTIR indicates the growth of functional bonding for wavelength 500-600 cm-1. The energy band gaps 1.47 eV and 1.18 eV are found by Touc plots which are suitable for optoelectronics. The dielectric constant, dielectric loss, and complex impedance of the samples were calculated. The impedance spectroscopy studies reveal the presence of orien-tational polarization in the samples at a low-frequency range. Moreover, theoretical calculations have been done by density functional theory and addressed the Half metallic ferromagnetism in A2FeMnO6(A= Ba, La). This ferromagnetism grows due to the exchange mechanism and hybridization of the electron's spin rather than the clustering effect. Finally, the optical properties are addressed by dielectric constants, and their dependence on parameters like absorption, refractive index, reflectivity, and optical loss.