Effect of Filler Concentration and Time Sonication of ZnO Composite for Radar Absorbing Material Applications

2021 ◽  
Vol 1028 ◽  
pp. 249-254
Author(s):  
Yus Rama Denny ◽  
Adhitya Trenggono ◽  
Teguh Firmansyah ◽  
Irvan Revaldi ◽  
Yana Taryana ◽  
...  
Keyword(s):  
Reflection Loss ◽  
Hexagonal Structure ◽  
Filler Concentration ◽  
Sonication Time ◽  
X Ray Diffraction ◽  
Radar Absorbing Material ◽  
Structure Morphology ◽  
Absorbing Material ◽  
Mixing Method ◽  
Absorption Percentage

Effects of filler concentration and sonication time on the structure, morphology, reflection loss and absorption percentage of ZnO composite was investigated. The structure, morphology, reflection loss and absorption percentage of the composite was investigated using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vector Network Analyzer (VNA). The ZnO composite was made by solution mixing method with the epoxy resin as a filler varied of 10 wt%, 20 wt%, and 30 wt%. The hardener was mixed to the ZnO composite by the composition of 2: 1. The sonication time was varied of 30, 45 and 60 minutes. The XRD showed that the crystal structure of ZnO composite was confirmed as a hexagonal structure and the structure was not change for all composite. The VNA results showed that the optimum reflection loss value was-9.37042 dB at the frequency of 12.3 GHz for the filler composition of 20 wt% and sonification time of 45 minutes. On the other hand, the minimum reflection loss value was-6.86845 dB at the frequency of 12.3 GHz for the filler composition of 10 wt% and sonification time of 45 minutes. In addition, the optimum absorption percentage was 18 % at a filler composition of 10 wt% with 60 minutes sonication time. This study demonstrates a promising method to improve a microwave absorption of ZnO composites.

scholarly journals Design of An Ultra-Thin and Broadband Absorption Materials For Middle-Temperature Applications

2021 ◽  
Author(s):  
Yanmin Jia ◽  
Zhaoning Yang ◽  
Lu Gao ◽  
Wei Ren ◽  
Ruiduan Zhang ◽  
...  
Keyword(s):  
Reflection Loss ◽  
Frequency Selective Surface ◽  
Complex Permeability ◽  
Frequency Range ◽  
Broadband Absorption ◽  
Radar Absorbing Material ◽  
Temperature Environment ◽  
Absorbing Material ◽  
Relationship Of ◽  
The Relationship

Abstract A radar absorbing material (RAM) is designed based on the magnetic ceramic and frequency selective surface (FSS). The phase composition and micromorphology were characterized, respectively. The complex permittivity and complex permeability of magnetic ceramic were tested and studied from 25 ℃ to 500 ℃ temperature. Based on the experimental and simulation results, the changes of reflection loss along with the structure parameters of RAM are analyzed at 500 ℃. The relationship of reflection loss varies with temperature are studied. The analytical results show that the absorption property of the RAM increases with the increase of temperature. An optimal absorption of RAM is obtained at 500℃. When the thickness of RAM is 1.5 mm, the reflection loss lower than -10 dB can be obtained in the frequency range from 8.2 ~ 16 GHz. More than 90% microwave energy can be consumed in the RAM which may be applied in the high temperature environment.

A Comparative Study on Process-Properties Correlation of Nano Radar Absorbing Heat Treated Materials

2009 ◽  
Vol 67 ◽  
pp. 39-44 ◽  
Author(s):  
Rahul Sharma ◽  
Ramesh Chandra Agarwala ◽  
Vijaya Agarwala
Keyword(s):  
Reflection Loss ◽  
Ostwald Ripening ◽  
Barium Hexaferrite ◽  
Precipitation Process ◽  
Morphological Transformation ◽  
Radar Absorbing Material ◽  
Quantum Size ◽  
Heat Treated ◽  
Absorbing Material ◽  
Co Precipitation

Single phase M-type barium hexaferrite nano radar absorbing material (NRAM) i.e., BaFe12O19 were synthesized by modified flux method that combines the controlled chemical co-precipitation process for nucleation and complete uniform growth during annealing with NaCl flux under microwave annealing (MWA) and vacuum annealing (VA). Uniform morphological transformation of nano crystals from spherical (~ 10 nm) to prism faces (~ 35 nm) were observed under TEM during annealing. The effect of such systematic nano morphological transformation of NRAM was observed on magnetic and reflection loss (RL) properties. Maximum reflection loss (RL) was improved to 37.15 dB at 16.00 GHz for MWA at 760 watt and 27.56 dB at 15.75 GHz for VA at 1200 oC with continuous increasing absorption range under −10 dB for 2 mm thick coating layer in the Ku Band (12.4-18.0 GHz).. Excellent microwave absorption properties are a consequence of accurate EM match in the nano morphological planes, a strong natural resonance, as well as multipolarization. This process of crystal growth, morphology evolution and RL enhancement with respect to the heat treatments were also explained in terms of Ostwald ripening and quantum size effect.

Analysis of Crystallography Structure and Magnetic Properties of Microwave Absorbing Material Ba0.6Sr0.4Fe12-3xZn2xTixO19 (X = 0, 0.2, 0.4, and 0.6)

2020 ◽  
Vol 855 ◽  
pp. 293-298
Author(s):  
Yohanes Edi Gunanto ◽  
Yosef Sarwanto ◽  
Wisnu Ari Adi
Keyword(s):  
Single Phase ◽  
Hexagonal Structure ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray ◽  
Absorbing Material ◽  
Coercivity Field ◽  
Size Of Particles

The synthesis and characterization of the Ba0.6Sr0.4Fe12-3xZn2xTixO19 microwave material with x = 0, 0.2, 0.4, and 0.6 has been successfully carried out. Samples were processed with the solid reaction method through milling at seven hundred revolutions per minute for five hours. X-ray diffraction was used to characterize the phase formation and crystal structure. Scanning electron microscopy was used to see the shape and size of particles, while the vibrating sample magnetometer was used to measure magnetic quantities, which are: the coercivity field and magnetic saturation. All samples have a hexagonal structure, for samples x = 0 and 0.2 have a single phase, while for samples x = 0.4 and 0.6 other phases are detected. The shape of the particles are heterogeneous, with size ranging from 10-25 μm. All samples were not saturated even until the external magnetic field reaches 1 T. As the value of x increases, the magnetization will decrease. Samples substituted by Zn and Ti (x ≠ 0) have higher coercivity field values when compared to sample without substitution (x = 0).

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

Structural and Magnetic Hysteresis Properties of Co-Zr Substituted Hexagonal Barium Ferrites

2015 ◽  
Vol 7 (1) ◽  
pp. 1346-1351
Author(s):  
Ch.Gopal Reddy ◽  
Ch. Venkateshwarlu ◽  
P. Vijaya Bhasker Reddy
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Magnetic Hysteresis ◽  
Grain Morphology ◽  
Hexagonal Structure ◽  
Ion Composition ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
Barium Ferrites ◽  
Xrd Patterns

Co-Zr substituted M-type hexagonal barium ferrites, with chemical formula BaCoxZrxFe12-2xO19 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), have been synthesized by double sintering ceramic method. The crystallographic properties, grain morphology and magnetic properties of these ferrites have been investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). The XRD patterns confirm the single phase with hexagonal structure of prepared ferrites. The magnetic properties have been investigated as a function of Co and Zr ion composition at an applied field in the range of 20 KOe. These studies indicate that the saturation magnetization (Ms) in the samples increases initially up to the Co-Zr composition of x=0.6 and decreases thereafter. On the other hand, the coercivity (Hc) and Remanent magnetization (Mr) are found to decrease continuously with increasing Co-Zr content. This property is most useful in permanent magnetic recording. The observed results are explained on the basis of site occupation of Co and Zr ions in the samples.

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

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