Observation of c-CuFe2O4 nanoparticles of the same crystallite size in different nanocomposite materials: The influence of Fe3+ cations

Two samples containing 2-line ferrihydrite and copper oxide were synthesized by coprecipitation method, via variation of Fe3+ and Cu2+ precursors milimolar ratio (3:1 and 3:3.1), while the other synthesis parameters were kept constant. Annealing treatment at 1100 °C resulted in the formation of c-CuFe2O4-CuO-α-Fe2O3 and c-CuFe2O4-CuO nanocomposites, respectively. A comparison of properties of the prepared samples was performed by XRD, FTIR and EPR measurements. Formation mechanism of the nanocomposites is discussed with a reference to the influence of Jahn-Teller effect in CuO phase on the final CuFe2O4 structure. For the first time, it is shown that the amount of Fe3+ precursor is of key importance for the size of CuFe2O4 nanoparticles, and enables preparation of c-CuFe2O4 nanoparticles of the same crystallite size (46 nm) in different nanocomposite materials. © 2019 Elsevier Inc