Influence of Cr3+ substitution on the electrical and magnetic properties of Ni0.4Cu0.4Zn0.2Fe2O4 nanoparticles

The Ni0.4Cu0.2Zn0.4 ferrites with different concentrations of Cr3+ were synthesized at a low temperature (450 degrees C) using sol-gel auto-combustion method. The X-ray diffraction analysis of the samples confirms the formation of a single-phase cubic spinel structure. The lattice constant decreases from 8.331 to 8.253 angstrom with an increase in Cr3+ substitution. Bulk density decreases from 4.95 to 4.71 gm/cm(3) whereas porosity increases from 9.34% to 14.76% with an increase in Cr3+ substitution. Transmission electron microscopy was adopted to determine the particle size. Particle size decreases from 19 to 13 nm with the addition of Cr3+ ions. Saturation magnetization, coercivity, and other hysteresis parameters were measured using a vibrating sample magnetometer at room temperature with a maximum magnetic field of 8 kOe. Magnetization decreases from 62 to 48 emu/g, whereas coercivity increases from 65 to 180 Oe. The direct current (DC) resistivity increases from 3.62 x 10(6) to 4.21 x 10(6) Omega cm with Cr3+ content x. The dielectric constant (epsilon ') decreases with increasing concentration of Cr3+ ions.