Study of Crystal Structure, Morphology, Magnetic and Electronic Structure of ZnFe2O4/CoCr2O4 Nanocomposites

In the present work, ZnFe2O4 and CoCr2O4 nanocomposites were prepared by the solution combustion synthesis method. The two materials were combined using the mechanical mixing method to produce nanocomposites with different weight ratios. The resulting nanocomposites were characterized by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), x-ray photoelectron spectroscopy (XPS), and zero-field-cooled (ZFC) and field-cooled (FC) magnetization. The XRD patterns confirmed the formation of a spinel structure, with average crystallite sizes of 35 nm and 20 nm, respectively. FESEM micrographs confirmed a non-spherical shape, homogeneous dispersion, and larger grain size. The XPS spectra were analyzed prior to determining the chemical composition of the (x)CoCr2O4+(1-x)ZnFe2O4 materials, revealing the occurrence of each element that appeared nominally in the formula. The hysteresis M-H curves for all tested samples at 10 K demonstrated S-type behavior, confirming the ferro-/ferrimagnetic order. It was noted that for the CoCr2O4 sample, the M-H loop at 90 K exhibited linear behavior, confirming the paramagnetic order, with a Curie temperature (T-C) of about 86 K. The experimental results indicate that the physical mixing process did not affect the phase purity of the nanoparticles, and the newly formed nanocomposites exhibited improved magnetic properties.