Structural and magnetic properties of ZnO–CoFe2O4 nanocomposites

•(CoFe2O4)x+(ZnO)1–x nanocomposites were prepared by the combustion reaction method.•Wurtzite and spinel lattice parameters change due the exchange of metallic ions between the two crystalline phases.•Strain was related to the content of cobalt ferrite.•Phonon Confinement Model (PCM) was used to explain the behavior of the E2high Raman mode.•Reduction of saturation magnetization with increasing of ZnO content was observed.

Nanocomposites with chemical composition (CoFe2O4)x+(ZnO)1–x were prepared by the combustion reaction method. X-ray diffraction data reveal the presence of only two crystalline nanosized phases with average diameters of ~55 nm (ZnO) and ~60 nm (CoFe2O4). The Rietveld method revealed that the molar ratio between the two phases shifted their nominal values from x=0.005, 0.050, 0.100, 0.200 and 0.400 up to x=0.030, 0.090, 0.170, 0.270 and 0.570, respectively. It was also found that the change of the lattice parameters of the wurtzite and spinel phases is related with the exchange of metallic ions between the two crystal structures. Our findings show that the ion exchange has direct influence on the vibrational and magnetic properties of the as-produced nanocomposites. Evidences supporting our findings are the appearance of vibrational modes induced by disorder and the decrease of the saturation magnetization.