Role of Zn substitution on structural, magnetic and dielectric properties of Cu-Cr spinel ferrites

The Zn substituted copper chromium spinel ferrites with the chemical formula ZnxCu1-xCr0.5Fe1.5O4 (x = 0-0.8) have been fabricated using powder metallurgical route. The synthesized powders have been investigated by thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy, magnetic and electrical measurement. The X-ray diffraction has confirmed the formation of spinel structure. It has been observed that lattice parameter increases but both the bulk and X-ray density decrease with the increase of Zn concentration. FTIR spectra show two prominent bands in the range of 400-800 cm(-1) confirming the formation of spinel ferrites. The saturation magnetization increases up to x = 0.4. As the concentration of Zn increases further, the saturation magnetization decreases. The dielectric tangent loss and dielectric constant (epsilon) decreases while the ac conductivity increases with increasing frequency.