Synthesis and Microwave Absorption Properties of BiFeO3 Nanowire-RGO Nanocomposite and First-Principles Calculations for Insight of Electromagnetic Properties and Electronic Structures

2017 ◽  
Vol 121 (39) ◽  
pp. 21290-21304 ◽  
Author(s):  
Debabrata Moitra ◽  
Samyak Dhole ◽  
Barun Kumar Ghosh ◽  
Madhurya Chandel ◽  
Raj Kumar Jani ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
First Principles ◽  
Electronic Structures ◽  
Electromagnetic Properties ◽  
First Principles Calculations ◽  
Absorption Properties ◽  
Microwave Absorption Properties

First-principles calculations of graphene-based polyaniline nano-hybrids for insight of electromagnetic properties and electronic structures

RSC Advances ◽  
2016 ◽  
Vol 6 (77) ◽  
pp. 73915-73923 ◽  
Author(s):  
Yuping Duan ◽  
Jin Liu ◽  
Yahong Zhang ◽  
Tongmin Wang
Keyword(s):  
Dielectric Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Microwave Dielectric Properties ◽  
First Principles Calculation ◽  
Electromagnetic Properties ◽  
First Principles Calculations ◽  
Microwave Dielectric

The microwave dielectric properties of graphene-based polyaniline hybrids are studied based on experiments and first-principles calculation.

FACILE SYNTHESIS AND MICROWAVE ABSORPTION PROPERTIES OF α-MnO2 NANORODS

2012 ◽  
Vol 05 (04) ◽  
pp. 1250043 ◽  
Author(s):  
HONGTAO GUAN ◽  
GANG CHEN ◽  
JING ZHU ◽  
YUDE WANG
Keyword(s):  
Microwave Absorption ◽  
Reflection Loss ◽  
Chemical Precipitation ◽  
Electromagnetic Properties ◽  
Precipitation Method ◽  
Electronic Microscopy ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
5 Ghz ◽  
Peak Value

A low-temperature water-bathing chemical precipitation method was developed to synthesize α- MnO2 nanorods. The morphological and crystalline structures were investigated by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and X-ray diffraction (XRD) spectra. The electromagnetic properties and microwave absorption properties were examined in the frequency range 2–18 GHz. The results show that the as-synthesized product is α- MnO2 nanorod with diameters of 30 nm and lengths up to 1–2 μm. The dielectric permittivity has a trend of decreasing its real and increasing its imaginary parts with the frequency. The magnetic permeability is about 1.0–1.2 and 0–0.1 for its real and imaginary parts at the whole frequency. With the increase of sample thickness, the reflection loss peak value shifts to lower frequency band. With a thickness of 3 mm, an absorption peak value of -25 dB was achieved. And its effective absorption bandwidth in which the reflection loss is lower than -10 dB is as high as 5 GHz.

PREPARATION AND ELECTROMAGNETIC PROPERTIES OF BaFe12O19–Ni0.8Zn0.2Fe2O4/POLYPYRROLE COMPOSITE FILM

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350022
Author(s):  
YAN WANG ◽  
YING HUANG ◽  
QIUFEN WANG ◽  
QIAN HE
Keyword(s):  
Composite Film ◽  
Microwave Absorption ◽  
Sulfonic Acid ◽  
Oxidative Polymerization ◽  
Sol Gel ◽  
Electromagnetic Properties ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Benzene Sulfonic Acid ◽  
Polypyrrole Composite

BaFe12O19 – Ni0.8Zn0.2Fe2O4 /Polypyrrole composite film [including three doping acids, dodecyl benzene sulfonic acid (DBSA), camphor sulfonic acid (CSA) and p-toluenesulfonic acid (TSA)] was prepared by sol–gel method and in situ chemical oxidative polymerization. The structure, morphologies, conductivities, magnetic properties and microwave absorption properties of the composite film were characterized by using XRD, FESEM, FTIR, Four-probe tester, VSM and Vector network analyzer. The results show that the conductivity of acid-doped Polypyrrole composite film is higher than that of pure Polypyrrole composite film. The saturation magnetization (Ms) and remanent magnetization (Mr) of the composite film are lower than those of BaFe12O19 – Ni0.8Zn0.2Fe2O4 film. However, the electromagnetic properties are in the contrary. The microwave absorption properties of the composite film are much better than those of BaFe12O19 – Ni0.8Zn0.2Fe2O4 , which mainly depends on the increasing of the dielectric loss. A minimum reflection loss of the DBSA-doped composite film is −17.6 dB at 9.3 GHz with the thickness at 3.0 mm.

Microwave Absorption Properties of Fe3O4-Graphene Nanohybrids

2017 ◽  
Vol 268 ◽  
pp. 297-301 ◽  
Author(s):  
Yau Thim Ng ◽  
Wei Kong ◽  
Sivanesan Appadu ◽  
Ing Kong
Keyword(s):  
Microwave Absorption ◽  
Magnetic Loss ◽  
Impedance Matching ◽  
Low Frequency ◽  
Electromagnetic Properties ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
In Situ Deposition

Magnetite (Fe3O4)-graphene nanohybrids having three different weight ratios of magnetite to graphene were synthesized by a facile in-situ deposition method. The combination of dielectric properties of graphene and magnetic properties of magnetite makes the nanohybrids an ideal choice of material for microwave absorption applications. In regards to that, the electromagnetic properties and microwave absorbing characteristics were investigated in a frequency range of 1-18 GHz. The reflection loss (RL) reaches a minimum of-40.44 dB at 6.84 GHz with a thickness of 7 mm for the sample containing 73 wt·% of Fe3O4. The bandwidth corresponding to the RL below-10 dB is 7.05 GHz. The as-prepared Fe3O4-graphene nanohybrids showed good microwave absorption ability in the low frequency band (C-band) which can be ascribed to improved impedance matching characteristics, enhanced interfacial polarizations as well as the magnetic loss contributions. Moreover, the frequency related to minimum RL could be tuned by varying the weight ratios of magnetite to graphene.

EFFECT OF CARBONIZATION TEMPERATURE ON DIELECTRIC AND MICROWAVE ABSORBING PROPERTIES OF COBALT DOPED MESOPOROUS CARBON COMPOSITES

NANO ◽  
2014 ◽  
Vol 09 (03) ◽  
pp. 1450033 ◽  
Author(s):  
QIAN LIAN ◽  
LIUDING WANG ◽  
HONGJING WU ◽  
HAO WU
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
Mesoporous Carbon ◽  
Carbonization Temperature ◽  
Electromagnetic Properties ◽  
Carbon Composites ◽  
Chemical Compositions ◽  
Ohmic Loss ◽  
Absorption Properties ◽  
Microwave Absorption Properties

Co doped mesoporous carbon composites (MC– Co ) have been synthesized at different carbonization temperatures via evaporation-induced multicomponent co-assembly strategy. The nanostructures and chemical compositions of MC– Co composites were characterized by transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction analysis (XRD), etc. Their electromagnetic and microwave absorption properties were investigated in the frequency ranging from 2 GHz to 18 GHz. By the measurement of electromagnetic parameters and theoretical simulation of reflection loss (RL), the results showed that the minimum RL value of the optimum composite MC– Co -800 reached up to -41.9 dB at 13.5 GHz with a thickness of only 1.80 mm, and the effective absorption bandwidth (< -10 dB) is 4.4 GHz (from 11.4 GHz to 15.8 GHz). This work demonstrated that the optimum carbonization temperature of the obtained composites is 800°C, which is critical to its electromagnetic properties. The excellent microwave absorption properties can be attributed to dielectric loss, Ohmic loss, and characteristic impedance matching. Therefore, the as-synthesized composites could be acted as a candidate of microwave absorber, especially for the light weight demand.

Preparation and Microwave Absorption Properties of LiZn Ferrite

2009 ◽  
Vol 25 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Hong JIANG ◽  
Jia GUO ◽  
Lu ZHAO ◽  
Hong ZHU
Keyword(s):  
Microwave Absorption ◽  
Absorption Properties ◽  
Microwave Absorption Properties
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