Understanding the structural, electronic, magnetic and optical properties of spinel MFe2O4 (M = Mn, Co, Ni) ferrites

Structural, electronic, magnetic and optical properties of MFe2O4 (M = Mn, Co, Ni) ferrites are studied by first-principles approach. MFe2O4 ferrites exhibit stable structure in ferromagnetic phase. Density of states (DOS) and electronic band structures reveal that all ferrites show favorable spin polarization behavior in applications point-of-view. The CoFe2O4 ferrite shows half-metallic ferromagnetic characteristics with direct band gap, E-g = 0.713 eV in spin up arrow state while NiFe2O4 shows spin gapless ferromagnetic behavior (with E-g = 0.0 at E-F) in spin up arrow state. The MnFe2O4 ferrite is found to have magnetically conducting behavior. MFe2O4 (M = Co, Ni) ferrites indicate 100% spin polarization at E-F. The electronic band structures reveal electronic transition between O-2p to Fe-3d states in valence band (VB) or d-d transition between Fe-3d valence and conduction bands. The optical properties shows that the MFe2O4 (M = Mn, Co, Ni) ferrites exhibit transparent behavior to ultraviolet light indicating their suitability for use in optical filters and sensors.