Structural and magnetic properties of CuFe₂O₄ as-prepared and thermally treated spinel nanoferrites

The copper based CuFe₂O₄ nanoferrite was prepared by chemical co-precipitation method and the detailed investigation of structural and magnetic properties was carried out successfully at room temperature. The obtained results from XRD confirm that CuFe₂O₄ has tetragonal structure at room temperature and its crystallite size, lattice strain was found to be varied from 11 to 17 nm and 3.9x10^-2 to 2.6x10^-2 for microwave annealed to as-prepared samples calculated using Scherrer equation and Williamson-Hall analysis, respectively. A clear superparamagnetic behaviour was observed in as-prepared and hot air oven annealed nanoferrite samples at RT under the field range of ±2 T. A distorted superparamagnetic curve was determined from isothermal magnetic hysteresis studies for the microwave oven annealed sample. It might be a possible magnetic and non-magnetic cation transformation on the surface of CuFe₂O₄ nanoparticles along with high lattice strain resulting in change of magnetic properties under certain level of applied magnetic field. (author)