Preparation of micro-nano hollow multiphase ceramic microspheres containing MnFe2O4 absorbent by self-reactive quenching method

Fe–Fe₂O₃–MnO₂–sucrose–epoxy resin and O₂ as reaction system and feed gas, separately, were used to prepare micro-nano hollow multiphase ceramic microspheres containing MnFe₂O₄ absorbent by self-reactive quenching method which is integrated with flame jet, self-propagating high-temperature synthesis (SHS), and rapidly solidification. The morphologies and phase compositions of hollow microspheres were studied by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and energy dispersive spectroscopy. The results show that the quenching products are regular spherical substantially with hollow structure, particle size is between few hundreds nanometers and 5 μm. Phase compositions are diphase of Fe₃O₄, Mn₃O₄, and MnFe₂O₄, and the spinel soft magnetic ferrite MnFe₂O₄ with microwave magnetic properties is in majority. Collisions with each other, burst as well as “refinement” of agglomerate powders in flame field may be the main reasons for the formation of micro-nano hollow multiphase ceramic microspheres containing MnFe₂O₄ absorbent.