Evolution of the structure, magnetic and optical properties of Ni1−xCuxFe2O4 spinel ferrites prepared by soft mechanochemical method

A series of Ni1−xCuxFe2O4 (0 ≤ x ≤ 0.9) nanoferrites were synthesized by mechanochemical technique. The impact of the Cu substitution on the spinel cubic structure and lattice constants were studied based on Cohen least square fit model. The particle size and stoichiometry were investigated by scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS). The substitution of Cu in Ni1−xCuxFe2O4 leads to the increase of particle size from 1.6 to 8.5 nm. The FTIR and Raman analysis revealed that the inclusion of Cu ions results in a migration of Fe ions from tetrahedral to octahedral sublattices. The magnetic (M-H) characteristics showed a remarkable enhancement of the saturation magnetization (37.8 emu/g) and coercive field (85.9Gauss) of the Ni0.5Cu0.5Fe2O4 sample. The optical properties were inspected by diffuse reflectance spectrophotometer. A decrease of the optical band gap from 2.62 eV to 1.57 eV as the content of Cu substitutions increases of 0-0.9 is monitored. The enhancement of the optical and magnetic properties of the Ni1−xCuxFe2O4 nanopowders enables them to be served as promising magneto-optical and magnetic catalysis materials.