Tuning Of Structural And Magnetic Properties Of Mn-Doped CoFe2O4 Nanoparticles

In the present manuscript, MnxCo1-xFe2O4 (x= 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) nanoparticles have been synthesized with co-precipitation method by annealing at 900 degrees C and studied the structural and magnetic properties. X ray diffraction pattern reveals the formation of single phase cubic spinel structure with the space group Fd-3m. An impurity peak of alpha-Fe2O3 has been observed in the XRD patterns of samples with Mn composition, x >= 0.4. However, this impurity phase of alpha-Fe2O3 is not observed in the MnFe2O4 sample synthesized by annealing at 500 degrees C. FESEM results indicate the formation of nano-sized particles. Magnetic measurements show ferrimagnetic interaction in MnxCo1-xFe2O4 (x >= 0) nanoparticles at room temperature. However, MnFe2O4 sample synthesized by annealing at 500 degrees C shows superparamagnetic behavior. We have fitted the M-H curve of MnFe2O4 synthesized by annealing at 500 degrees C with modified Langvenin function to confirm superparamagnetism. The correlation between the structural and observed magnetic properties of as synthesized samples nanoparticles will be described and discussed in this paper.