Enhanced Microwave Absorption at Low Frequency of Superparamagnetic Fe_3O_4 Single Nano-crystals

摘要

The superparamagnetic Fe_3O_4 single nanocrystals with diameters of 10-15 nm have been synthesized via a simple method. Several characterizations such as SEM, TEM and XRD are used to obtain the morphology and crystallinity of Fe_3O_4 nanoparticles. The investigation about wave absorption property indicates that Fe_3O_4 nanocrystals is an excellent absorber, the effective frequency band (RL<-5.30 dB) of absorbers are obtained in a broad frequency range from 2.0 GHz to 15.40 GHz and the minimum reflection losses and the peak frequencies are -10.5 dB and -7.7 dB at the frequency of 10.4 GHz and 14.1 GHz, respectively.