Synthesis and physical investigation of Mnx Zn1-xFe2O4 magnetic nanopowders coated with organic shell

Magnetic materials in the form of colloidal nanoparticles have received much attention due to their remarkable magnetic proprieties, which are dominated by superparamagnetism; these materials being used in various technical and biomedical fields, including the preparation of stable magnetic fluids. Co-precipitation from metal salts solutions is a rather simple and available method, which was widely applied in the frame of our study and resulted in nanopowders of Mn (x) Zn1-x Fe2O4 (x = 0.9, 0.7, 0.5, and 0.3). Microstructural and magnetic investigations were carried out to reveal nanometric sizes of magnetic grain/nonmagnetic shell systems. Different dependences on the manganese fraction of the saturation magnetization, on one side, and crystallite size and magnetic coercivity, on the other side, were evidenced.