Micro-structural, dielectrical and magnetic properties of Cu2+ substituted Ni0.7Mn0.3-xCuxFe2O4 (x = 0.0, 0.05, 0.1, 0.15 and 0.2) nano-ferrites

Abstract

The nano-ferrites with chemical formula Ni0.7Mn0.3-xCuxFe2O4 having × between 0.0 and 0.2 were prepared by sol-gel auto-combustion process. The XRD pattern presents quite a good evidence for the formation of ferrite spinel phase in all the prepared samples. The broad lines indicate that the particles are of nano-size. The SEM studies reveal about the uniformity and crystallinity of the materials and also the spherical shape of the grains. Rise in copper density leads to fall in dielectric constant (εr) due to the relocation of Fe3+ from B-position to A-position. The dielectric loss (tan δ) maxima location swings towards the lower frequency as composition of dopant rises. The saturation magnetization and net magnetic moment decline with rise in Cu composition. The ESR technique ropes the subsistence of non collinear magnetic structure as predicted by VSM measurements.