Integrating hierarchical interfacial polarization in yeast-derived Mo2C/C nanoflower/microsphere nanoarchitecture for boosting microwave absorption performance

Abstract xAl2O3-(1-x)Sr0.85Gd0.15TiO3(x=0.2, 0.3, 0.4, 0.5) ceramics were fabricated by hot-press sintering. Their morphology, phase composition, conductivity, dielectric properties as well as microwave absorption performance were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), multifunction digital four-probe meter and vector network analysis, respectively. The microwave absorption of as-prepared xAl2O3-(1-x)Sr0.85Gd0.15TiO3 ceramics demonstrates excellent microwave absorbability. It is unexpectedly found that with a thickness of only 0.346 mm, xAl2O3-(1-x)Sr0.85Gd0.15TiO3 (x=0.2) ceramic exhibits an absorption bandwidth of 3.7 GHz (8.7-12.4 GHz), being consequential to reflection loss less than -10 dB (over 90% of microwave absorption). It is as well discovered that the minimum reflection loss and absorption peak frequency of xAl2O3-(1-x)Sr0.85Gd0.15TiO3 (x=0.3) with a thickness of 0.436 mm were -45.43 dB and 11.3 GHz, respectively. The prominent microwave absorption performance of the ceramic with such a thin thickness can be attributed to strong interfacial polarization, dielectric frequency dispersion, and good electromagnetic impedance matching. It indicates that the xAl2O3-(1-x)Sr0.85Gd0.15TiO3 ceramics with appropriate Al2O3 mass fraction and thickness showing good potential for effective microwave absorbing materials.

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An Easy Method of Synthesis CoxOy@C Composite with Enhanced Microwave Absorption Performance

Nanomaterials ◽

10.3390/nano10050902 ◽

2020 ◽

Vol 10 (5) ◽

pp. 902

Author(s):

Wenli Bao ◽

Cong Chen ◽

Zhenjun Si

Keyword(s):

Microwave Absorption ◽

Impedance Matching ◽

Interfacial Polarization ◽

Magnetic Composite ◽

Easy Method ◽

Electromagnetic Absorption ◽

Absorption Performance ◽

Matched Impedance ◽

Microwave Absorption Performance ◽

Minimum Reflection Loss

Design of interface-controllable magnetic composite towards the wideband microwave absorber is greatly significance, however, it still remains challenging. Herein, we designed a spherical-like hybrids, using the Co3O4 and amorphous carbon as the core and shell, respectively. Then, the existed Co3O4 core could be totally reduced by the carbon shell, thus in CoxOy core (composed by Co and Co3O4). Of particular note, the ratios of Co and Co3O4 can be linearly tuned, suggesting the controlled interfaces, which greatly influences the interface loss behavior and electromagnetic absorption performance. The results revealed that the minimum reflection loss value (RLmin) of −39.4 dB could be achieved for the optimal CoxOy@C sample under a thin thickness of 1.4 mm. More importantly, the frequency region with RL < −10 dB was estimated to be 4.3 GHz, ranging from 13.7 to 18.0 GHz. The superior wideband microwave absorption performance was primarily attributed to the multiple interfacial polarization and matched impedance matching ability.

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Efficient microwave traps with markedly enhanced interfacial polarization and impedance matching enabled by dual-shelled, dual-cavity magnetic@dielectric hollow nanospheres

Journal of Materials Chemistry C ◽

10.1039/d0tc03533e ◽

2020 ◽

Vol 8 (46) ◽

pp. 16489-16497

Author(s):

Jiasong Hua ◽

Wenjun Ma ◽

Xiaoyun Liu ◽

Qixin Zhuang ◽

Zeyang Wu ◽

...

Keyword(s):

Microwave Absorption ◽

Reflection Loss ◽

Impedance Matching ◽

Interfacial Polarization ◽

Hollow Nanospheres ◽

Absorption Performance ◽

Microwave Absorption Performance ◽

Magnetic Dielectric ◽

Minimum Reflection Loss

Dual-shelled, dual-cavity Fe3O4@TiO2 hollow nanospheres exhibit an outstanding microwave absorption performance with a minimum reflection loss of −60.17 dB.

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Integrating Hierarchical Interfacial Polarization in Yeast-Derived Mo 2C/C Nanoflower/Microsphere Nanoarchitecture for Boosting Microwave Absorption Performance

SSRN Electronic Journal ◽

10.2139/ssrn.3969608 ◽

2021 ◽

Author(s):

Zhengchen Wu ◽

Chen Jin ◽

Ziqi Yang ◽

Renchao Che

Keyword(s):

Microwave Absorption ◽

Interfacial Polarization ◽

Absorption Performance ◽

Microwave Absorption Performance

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Effect of Reaction Time on Microwave Absorption Properties of Fe3O4 Hollow Spheres Synthesized via Ostwald Ripening

Materials ◽

10.3390/ma12182921 ◽

2019 ◽

Vol 12 (18) ◽

pp. 2921 ◽

Cited By ~ 1

Author(s):

Wei Huang ◽

Yujiang Wang ◽

Shicheng Wei ◽

Bo Wang ◽

Yi Liang ◽

...

Keyword(s):

Reaction Time ◽

Microwave Absorption ◽

Ostwald Ripening ◽

Impedance Matching ◽

Hollow Spheres ◽

Absorption Properties ◽

Microwave Absorption Properties ◽

Magnetic Structures ◽

Absorption Performance ◽

Microwave Absorption Performance

Hollow magnetic structures have great potential to be used in the microwave absorbing field. Herein, Fe3O4 hollow spheres with different levels of hollowness were synthesized by the hydrothermal method under Ostwald ripening effect. In addition to their microstructures, the microwave absorption properties of such spheres were investigated. The results show that the grain size and hollowness of Fe3O4 hollow spheres both increase as the reaction time increases. With increasing hollowness, the attenuation ability of electromagnetic wave of Fe3O4 spheres increases first and then decreases, finally increases sharply after the spheres break down. Samples with strong attenuation ability can achieve good impedance matching, which it does preferentially as the absorber thickness increases. Fe3O4 hollow spheres show the best microwave absorption performance when the reaction time is 24 h. The minimum reflection loss (RL (min)) can reach −40 dB, while the thickness is only 3.2 mm.

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