Preparation and characterization of flaky NiFe-diatomite magnetic composite particles

Amorphous silica porous structure of the disk-shaped diatom shell has the property of large specific surface area and light weight. It is possible to prepare a high-quality functional magnetic particles by combining the high permeability ferrite material with diatom shell. In this paper, according to thermal decomposition principle of iron pentacarbonyl change to iron atoms and carbon monoxide at high temperature, using dropping method and steaming method with N₂ carrying, the feasibility of diatom shell particles deposited metal surface iron were explored. The scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and vibrant sample magnetometer (VSM) were used to make clear their morphology microstructure, chemical composition, crystal structure, and magnetostatic characteristic. Experimental results showed that the magnetic functional of diatom shell by thermal decomposition limited forming method of iron pentacarbonyl could be achieved. Moreover, the uniformly iron coated magnetic particles were fabricated by steaming method with N₂ carrying with the saturation magnetization Ms at 118 A·m²/kg and coercive force Hc at 2.39×10⁴ A/m.