Structural, magnetic and dielectric study of La3+ substituted Cu0.8Cd0.2Fe2O4 ferrite nanoparticles synthesized by the co-precipitation method

Abstract

In this paper, a series of Cu-Cd-La nanostructured ferrites having composition Cu0.8Cd0.2Fe2-yLayO4 (y = 0.000–0.075) was synthesized by co-precipitation technique. The influence of La3+ doping on the structural, magnetic and dielectric properties of Cu-Cd ferrite nanoparticles was studied by XRD, FTIR, VSM and Dielectric measurements. Single-phase spinel structure of Cu0.8Cd0.2Fe2-yLayO4 ferrite nanoparticles is confirmed by the x-ray diffraction measurements. It is found that crystalline size increases up to doping concentration y = 0.015 and then decreases for higher concentration of La3+ contents in Cu-Cd ferrites. Increase in lattice constant is attributed to larger atomic radius of La3+ as compared to Fe3+ ion and decrease in lattice constant is attributed to the higher La3+ concentration that is linked with the appearance of grain boundaries. FTIR spectra reveal two bands (ʋ1 = 554.18 cm−1 ʋ2 = 483.49 cm−1) that corresponds to tetrahedral and octahedral sites, respectively, in all the prepared Cu-Cd ferrites. VSM measurements showed that the Coercivity and Saturation magnetization deceases with the concentration of La3+ ions. Dielectric parameters tend to decrease at higher frequency and a maximum is observed at a frequency 1.5 × 109 Hz. Dielectric constant, dielectric loss and dielectric loss tangent were calculated as a function of frequency and explained on the basis of Koop's theory. AC conductivity is found to increase with the frequency but at higher frequencies, ac conductivity start to decreases.