Characterization and Preparation of Fe₃O₄/MnO₂ Composite Magnetic Particles

Using nano-Fe3O4 particles as cores,Fe3O4/MnO2 composite particles that MnO2 coating on the cores were prepared by fluid deposition method and sol-gel method.The structure and morphology of the nano-Fe3O4 particle and composite particles were characterized by the means of XRD,TEM,FTIR and VSM.The results indicate that the size of Fe3O4/ MnO2 composite particles prepared by fluid deposition method and contained several Fe3O4 particles as core was about 200 nm,and the size of the composite particles prepared by sol-gel method was about 50 nm.The saturated magnetizations of Fe3O4/MnO2 composite particles were 24.7 kA·m-1 and 16.5 kA·m-1 respectively.