Characterization of Ni-Cu mixed spinel ferrite

Crystal structure, X-ray density, porosity, compressive strength of Ni1-xCuxFe2O4 have been investigated along with scanning electron microscopy (SEM) to study the effect of composition and microstructure on the magnetic and electrical properties. The formation of single-phase ferrite is confirmed by the X-ray diffraction. Tetragonal deformation is observed for the sample of composition x = 1, i.e. for pure CuFe2O4 Crystal structure for samples of other compositions are face centered cubic (FCC). SEM micrographs exhibit increase in grain size with the increase of copper content. Compressive strength decreases with the increase of Cu. Initial magnetic permeability and saturation magnetization is maximum for the composition of x = 0.2, i.e. for Ni0.8Cu0.2Fe2O4, which can be attributed to the maximum sintered density obtained for this composition. Resistivity decreases with the increase of Cu content. (C) 2002 Elsevier Science B.V. All rights reserved.