6 Nanocomposites and nanomaterials

Influence of synthesis pH on the magnetic properties of copper ferrite

L. A. Frolova, O. A. Pivovarov

Department of Technology Inorganic Materials and Ecology, 
Ukrainian State University of Chemical Technology, ave Gagarina, 8, Dnipro-49005, Ukraine.
Email: 19kozak83@gmail.com

Copper ferities a magnetic material that is stable, relatively inexpensive, easy to manufacture and widely used in electronics, radio electronics, catalysis, and medicine. Successful use in these fields requires the presence of appropriate electrical and magnetic properties, which are due primarily to the structure. The technology of producing copper ferrite has been widely studied for many years. Many different synthesis methods have emerged, such as microemulsion, co-precipitation, sol-gel, hydrothermal, sonochemical, which allow obtaining ferrite at low temperatures. Moreover, the development of new methods for the synthesis of CuFe2O4 is of great importance due to the possibility of it uses as gas sensors, catalysts, in lithium-ion batteries, high-density recorders, magnetic liquid.
This study proposes a plasma method that has a number of advantages, such as short duration, product purity, simplicity, energy efficiency and high dispersion of the final product.
CuFe2O4 nanoparticles were prepared by chemical precipitation from aqueous ferrous sulphate solution and copper(II) sulfate and treatment the suspensions in the reactor under the action of plasma discharge for forty minutes. Changes in pH and potential were measured every two minutes. According to the obtained data, graphs dependence pH - processing time and potential - processing time were constructed. The composition of the obtained products was determined by X-ray phase analysis. Hysteresis loops were constructed and magnetic characteristics were determined
So the method of producing copper ferrite using non-equilibrium contact plasma can allow a fairly high degree of ferritization to be achieved. 
The value of coercive force and magnetic saturation is determined by the phase composition of the compounds that are formed. In the pH range from 7 to 9, non-magnetic complex oxides and Fe-Cu oxyhydroxides are formed. By increasing the initial pH of the final products are copper ferrites, which have magnetic properties. Increasing the pH to 12 leads to a decrease in magnetic saturation due to the formation of a mixed oxide-ferrite phase.