Facial Synthesis of Zn-Doped Fe₃O₄ with Enhanced Electromagnetic Wave Absorption Performance in S and C Bands

Abstract

In this study, Zn-doped Fe3O4 nanoparticles were successfully synthesized by a facile solvothermal method in the presence of sodium dodecyl sulfate (SDS). The morphology, magnetic properties and electromagnetic wave absorbing properties of these materials were characterized. Results showed that Zn[Formula: see text] played a significant role in the formation of Zn-doped Fe3O4. With the protection of SDS, highly dispersed Fe3O4 nanoparticles were obtained. The nanoparticle size decreased after Zn[Formula: see text] doping, and the dispersity deteriorated with increasing Zn[Formula: see text] doping concentration. Zn-doped Fe3O4 exhibited excellent electromagnetic wave absorbing property, which resulted in magnetic loss and dielectric loss at an appropriate doping concentration. The minimum reflection loss (RL) was approximately [Formula: see text][Formula: see text]dB at 16.9[Formula: see text]GHz. As the coating layer thickness increased to 4.0[Formula: see text]mm, the bandwidth was approximately 5.0[Formula: see text]GHz corresponding to RL below [Formula: see text][Formula: see text]dB, which nearly covered the entire S band (2–4[Formula: see text]GHz) and C band (4–8[Formula: see text]GHz). The peak frequency of RL and the number of peaks matched the quarter-wave thickness criteria. It was believed that the Zn-doped Fe3O4 could be a potential electromagnetic wave absorbing material in S and C bands.

Facile Synthesis of Polyindole/Ni1–xZnxFe2O4(x= 0, 0.5, 1) Nanocomposites and Their Enhanced Microwave Absorption and Shielding Properties

“…Therefore, the difference between the T B and T irr values reveals the contribution of the larger particles (broad particle size magnetization as they unblock at higher temperatures and development of ferromagnetic clusters in the NZF nanoparticles). The ZFC curve of ZF nanoparticles (Figure c) shows a cusp at the blocking temperature T B = 16.3 K, as expected for superparamagnetic nanoparticles, below which the system is blocked . However, the large difference between T B and T irr (at 240 K) is an indication of the existence of ferromagnetic clusters in the ZF nanoparticle system.…”

“…For the NZF nanoparticles (Figure b), M ZFC shows only a small decrease with a broad maximum at T B = 56.2 K, above which the system shows superparamagnetic behavior. Interestingly, the feature that M FC remains nearly flat below T B indicates a system with low anisotropy. , Also, magnetic irreversibility between ZFC and FC curves can be noticed from T B up to T irr = 245 K, where both curves merge. T irr corresponds to the highest blocking temperature, that is, to that of the largest nanoparticles in the superparamagnetic system with the highest energy barrier .…”

“…The ZFC curve of ZF nanoparticles ( Figure 7 c) shows a cusp at the blocking temperature T B = 16.3 K, as expected for superparamagnetic nanoparticles, below which the system is blocked. 36 However, the large difference between T B and T irr (at 240 K) is an indication of the existence of ferromagnetic clusters in the ZF nanoparticle system. Furthermore, it is noted that T B decreases in the order T B NF > T B NZF > T B ZF.…”

“…In recent years, researchers have had a great interest in spinel ferrite nanoparticles due to their extensive applications in gas sensing, inductors, biosensing, sequestration of lanthanides and actinides from aqueous solutions, telecommunications, and hyperthermia applications in cancer therapy . Magnetic nanoparticles such as Fe 3 O 4 , − ZnFe 2 O 4 , , NiFe 2 O 4 , − and (NiZn)­Fe 2 O 4 , are well-known traditional microwave absorbers, proven to have significant magnetic loss properties. Due to their low eddy current losses, they show wide electronic applications in terms of power generation, conditioning, and conversion .…”

Structure and Microwave Absorption Properties of Polyaniline/Zn Ferrite Composites

“…Zn ferrite show better microwave attenuation capability than Fe 3 O 4 in our early report, 21 hence, combining Zn ferrite with PANI may have a surprising e®ect on microwave attenuation performance. In this study, Zn ferrite was used to adjust the impedance matching and improve PANI magnetic loss capability.…”