Microwave Combustion Synthesis and Characterization Studies of Magnetic Zn1-xCdxFe2O4 (0 ≤ x ≤ 0.5) Nanoparticles

Nano-sized pure and Cd-doped ZnFe2O4 (Zn1-xCdxFe2O4 with x = 0.0-0.5) samples were synthesized by a simple microwave combustion method. The X-ray diffraction (XRD) analysis confirmed the single phase cubic spinel structure. The average crystallite size was found in the range of 17.47-41.21 nm. The lattice parameter is found to increase with increase in the concentration of Cd. Pure ZnFe2O4 and all compositions of the Zn-Cd ferrites showed similar particle-like morphologies, which is confirmed by high resolution scanning electron microscopy (HR-SEM). Energy dispersive X-ray (EDX) analysis shows that the theoretical and observed percentage of the elements; Zn2+, Cd2+ and Fe3+ are in the desired stoichiometric proportion. The UV-Visible diffuse reflectance spectrum (DRS) shows the band gap value increases with increasing Cd content. All the samples showed the characteristic near-band-edge emission at around 428 nm, which is observed by photoluminescence (PL) spectra. The magnetic properties were measured by using vibrating sample magnetometer (VSM) and it was found that the saturation magnetization is increased with increase the concentration of Cd content. The results revealed that for lower Cd concentration (x = 0.0-0.2) the samples shows a superparamagnetic behavior, whereas for higher concentration (x = 0.3-0.5), it becomes ferromagnetic.