Abstract: The monodispersed magnetic Fe3O4 hollow submicro-spheres were prepared by directly pyrolyzing the P(St-co-AA)/Fe2O3 core-shell particles in nitrogen, which were obtained by controlled hydrolysis of FeCl3 on the surface of template particles. The structure, composition and magnetic properties of those hollow spheres were examined by transmission electron microscopy(TEM), field emission scanning electron microscopy(FESEM), X-ray diffraction(XRD) and vibrating sample magnetometer(VSM) etc. The results showed that the monodispersed Fe3O4 hollow submicro-spheres with even and compact shells were produced since the Fe2O3 shells were deoxidized into Fe3O4 by the pyrolysates decomposed from the polymer cores during heat-treatment in nitrogen gas. The Fe3O4 hollow particles showed saturated magnetization of 50.91 A·m2·kg -1, remaining magnetization of 3.97 A·m2·kg -1 and coercivity of 2.33 kA·m-1 at roomtemperature.

Key words: Fe3O4； Hollow sub-microspheres； Pyrolysis-deoxidization； Magnetism