Investigation on lanthanum substitution in magnetic and structural properties of group IV elements

Concerning to the profuse applications in the field of magnetic materials, group N elements have received a significant attention owing to its chemical stability and high electrical resistivity. In this investigation, appropriation of rare earth (Lanthanum) has been substituted in NiFe2O4 and CuFe2O4, which has a large ionic radii and the spinel lattice could prominently influence the structural, optical and magnetic properties of ferrite crystals. These nanocrystals are prepared via co-precipitation route. The structural property of the samples were characterized by XRD, as the La doped NiFe2O4 had a small crystallite size when compared to CuFe2O4, doped La inhibits the grain growth of the NiFe2O4 in efficient manner compared with that of CuFe2O4 nanocrystal. FTIR shows two absorption bands in tetrahedral and octahedral sites. UV visible spectra depicts the absorbance of lanthanum doped NiFe2O4 and CuFe2O4 nanoparticles with the band-gap ranging from 2.1 to 2.3 eV. The morphology was studied using TEM. The magnetic parameters have been studied using Vibrating sample magnetometer. The effects of the change in magnetic structures on the surface of the nanocrystals and the contribution from single ion anisotropy of lanthanum ions present in the crystal lattice were found using Vibrating sample magnetometer.