Hierarchical magnetic yolk-shell microspheres with mixed barium silicate and barium titanium oxide shells for microwave absorption enhancement

A facile hydrothermal-assisted crystallization route for the synthesis of hierarchical magnetic yolk-shell microspheres with mixed barium silicate and barium titanium oxide shells has been developed. Various yolk-shell microspheres with different shell thicknesses and core sizes have been successfully synthesized by controlling the synthetic parameters. The as-synthesized yolk-shell microspheres possess high magnetization, tailored shells, large specific surface area and high porosity, and are demonstrated to be attractive candidate materials for microwave absorption enhancement. Moreover, a possible formation mechanism based on the sacrificial-templating crystallization, dissolution-precipitation and in situ transformation processes is proposed.