Synthesis and microwave magnetic properties of a-Fe/ferrite composites with sandwich structure

A new kind of a-Fe/ferrite composites with sandwich structure was realized by chemical reduction method, where the as-prepared W-type barium hexaferrite flake particles were subjected to a reduction treatment in hydrogen atmosphere at different temperatures. X-ray diffractometer reveals that a-Fe/Co particles precipitate in the ferrite matrix, when the reduction temperature is higher than 230 deg. C. With the temperature increased, the particles morphology changed into sandwich structure in hexagonal flake particles and the barium hexaferrite phase was decomposed gradually, when were completely decomposed at T=450 deg. C. Results show that the composites particles with sandwich structure (T=270 deg. C) have higher microwave complex permeability than the others