Structural, electronic, magnetic, and optical properties of MFe2O4 (M = Ni, Fe, Co) spinel ferrites: A density functional theory study

The structural, electronic, magnetic, and optical properties of MFe2O4 (M = Ni, Fe, Co) ferrites were investigated by employing Cambridge Serial Total Energy Package code using density functional theory. LDA+U was used to investigate the structural, electronic, magnetic, and optical properties of MFe2O4 (M = Ni, Fe, Co) ferrites at different pressures 0, 5, 10, 15, and 20 GPa. The simulated X-ray diffraction (XRD) pattern of MFe2O4 (M = Ni, Fe, Co) ferrites was investigated and the computed lattice parameters decreased 8.62-8.32, 8.68-8.35, and 8.567-8.267 angstrom at 0-20 GPa, respectively. XRD revealed that the unit cell's volumes (640.50-575.93, 653.97-582.182, 627.22-563.550), X-ray densities (4.86-5.40, 4.70-5.28, 3.97-4.43), and interatomic distance (2.6099-2.5180, 2.6221-2.4260, 2.5831-2.4928) of MFe2O4 (M = Ni, Fe, Co) ferrites were also decreased with the increasing pressure 0-20 GPa, respectively. The LDA+U calculations predicted that the NiFe2O4, Fe3O4, and CoFe2O4 ferrite followed the properties of a semiconductor exhibiting a direct band gap of 1.2, 1.13, and 0.710 eV at 0 GPa which were decreased to 0.846, 0.710, and 0.461 eV at 20 GPa, respectively. The computed density of states revealed that MFe2O4 (M = Ni, Fe, Co) ferrites exhibited good spin polarization behavior, and Ni-O, Fe-O, and Co-O bonds were covalent. The Mullikens investigated the ted decrease in bong length of MFe2O4 (M = Ni, Fe, Co) ferrites versus 0-20 GPa as well as according to Hirschfeld analysis the magnetic moment (3.348-3.335, 4.12-4.10, 3.737-3.735) and saturation magnetization (79.06-78.7, 99.33-98.9, 88.93-88.352) of MFe2O4 (M = Ni, Fe, Co) ferrites were decreased with increased pressure 0-20 GPa, respectively. The reflectivity and absorption specialize in visible and ultraviolet regions showing their stability for optoelectronics, photocatalysis, and solar cell applications.

Automated summary

The structural, electronic, magnetic, and optical properties of MFe2O4 (M = Ni, Fe, Co) ferrites were studied using density functional theory. LDA+U was employed to investigate these properties under different pressures. XRD patterns revealed a decrease in lattice parameters, unit cell volumes, X-ray densities, and interatomic distances with increasing pressure. LDA+U calculations showed that the ferrites exhibited semiconductor behavior with a decrease in band gap as pressure increased. The magnetic properties, including magnetic moment and saturation magnetization, also decreased with increasing pressure. The ferrites were found to be suitable for optoelectronic, photocatalytic, and solar cell applications.