Synthesis of layered Fe_3O_4 nanodisk and nanostructure dependent microwave absorption property

摘要

Fe_3O_4 nanodisks with plate and layered hierarchical nanostructure were successfully synthesized by the reduction of the layered α-Fe_2O_3 nanodisk. The microwave absorb ability could be well modulated by mainly tuning the nanostructure of the Fe_3O_4 nanodisks. The minimum reflection loss (RL) of layered Fe_3O_4 nanodisks reaches - 14.8 dB at an extremely low mass fraction (about 10%), which is better than - 10.0 dB obtained using plate Fe_3O_4 nanodisks. The dielectric loss plays a critical role in the structure-dependent RL ability, caused by the enhanced multiple reflections in the absorber and an increase of the dipoles, interfacial polarization, and the associated relaxation. Such layered Fe_3O_4 nanodisks open a new avenue to exploit new microwave devices.