Structural and magnetic analysis of Cd-Zn spinel ferrite nanoparticles

Sol-gel auto-combustion synthesis technique was employed to synthesize Cd-Zn ferrite nanoparticles with composition Zn1-xCdxFe2O4, where 0.0 <= x <= 1.0. The physical properties of prepared samples were inspected by using x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and vibration sample magnetometer (VSM) techniques. XRD analysis confirmed the formation of Cd-Zn spinel nanoferrites with an increase in experimental lattice constant from 8.37 angstrom to 8.74 angstrom for zinc and cadmium ferrite samples, respectively. Variation of tetrahedral and octahedral hopping lengths, crystallite size, microstrain and dislocation density with Cd-content has been investigated and elucidated. SEM micrographs showed agglomeration of nearly-spherical grains that increased in size with Cd-content increase. FTIR analysis confirmed the existence of the characteristic tetrahedral and octahedral stretching vibrations of metal ion and oxygen complex in the range 429-558 cm(-1). VSM measurements revealed a tuning in coercivity to higher values and a decrease in saturation magnetization as Cd-content increased. The calculated cations distribution, bond lengths, bond angles and interionic distances between cations at tetrahedral and octahedral sites attribute the observed decrease in saturation magnetization to weak interaction between cations in the two sites.