Preparation and characteristics of Fe3O4-encapsulated BaTiO3 powder by ultrasound-enhanced ferrite plating

Abstract Fe3O4-encapsulated BaTiO3 composite powders were prepared with ultrasound-enhanced ferrite plating. It was observed that Fe3O4 particles of a single magnetite phase grew in a spherical form on BaTiO3 grains. Microwave absorbing behavior of the composite powders depended strongly on a plating condition such as the concentration of buffer (CH3COONH4) solution. When the buffer concentration was 0.2 M, Fe3O4 particles densely coated the BaTiO3 grains, which in turn exhibited two microwave absorption bands at 8 and 13 GHz with the reflection losses of −24 and −8 dB, respectively.