Development of Electroless Ni-P/NRAM Nanocomposite Powder with Enhanced Microwave Absorption Properties

2009 ◽  
Vol 67 ◽  
pp. 59-64 ◽  
Author(s):  
Rahul Sharma ◽  
Ramesh Chandra Agarwala ◽  
Vijaya Agarwala
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
Radiation Power ◽  
Nanocomposite Powder ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Radar Absorbing Material ◽  
Transmission Electron ◽  
Absorbing Material ◽  
Nanocomposite Powders

Nano radar absorbing material (NRAM) i.e. BaMe2Fe16O27 (Me2+=Fe2+) powder (10 nm) is coated with amorphous Ni-P nano layer (5-10 nm) by using electroless (EL) technology to develop EL Ni-P/NRAM nanocomposite powder. The experimental processes parameters and EL Ni-P bath composition were optimized to obtain the deposition. As-deposited nanocomposite powder was microwave annealed (MWA) with increasing radiation power from 160 to 760 watts for 5 minutes. The surface morphology, elemental contents, phase transformation and magnetic properties of NRAM powders were examined under field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) respectively. Maximum reflection loss (RL) 33.75 dB at 15.80 GHz for nanocomposite powder MWA at 760 watt was obtained the absorption range under −15 dB is from 13.76 to 16.77 GHz with 2 mm thickness layer in Ku Band. Excellent microwave absorption properties due to accurate electromagnetic (EM) match in the nanocomposite microstructure, a strong natural resonance and multipolarization. Such (Ni+ Ni3P)/NRAM nanocomposite powders may be attractive candidates for EM absorption.

MICROWAVE ABSORPTION BEHAVIOR OF MESOPOROUS TRANSITION METAL OXIDE TEMPLATED FROM SBA-15 AND KIT-6

2014 ◽  
Vol 28 (10) ◽  
pp. 1450037 ◽  
Author(s):  
HONGJING WU ◽  
LIUDING WANG ◽  
YIMING WANG
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
Absorption Characteristic ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Hard Template ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
X Ray ◽  
Transmission Electron

In this paper, we have synthesized meso-oxides (i.e., Co 3 O 4 and NiO ) by using mesoporous silica as hard template. The microstructures and chemical compositions of the corresponding meso-oxides were characterized by the Transmission electron microscope-selected area electron diffusion (TEM-SAED), X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), respectively. And, their electromagnetic and microwave absorption properties were investigated in the frequency range of 2–18 GHz. The results indicate that meso-oxide templated from KIT-6 (i.e., meso-K– Co / Ni ) exhibit a dual absorption characteristic compared with those using SBA-15 as hard template. This phenomenon suggests that meso-oxides templated from SBA-15 and KIT-6 can exhibit different microwave absorption behaviors due to their respective microstructures.

Synthesis, Characterization, and Microwave Absorption Properties of SrFe12O19 Ferrites and FeNi3 Nanoplatelets Composites

2010 ◽  
Vol 148-149 ◽  
pp. 893-896 ◽  
Author(s):  
Ze Yang Zhang ◽  
Xiang Xuan Liu ◽  
You Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Microwave Absorption ◽  
Composite Coatings ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Filling Fraction ◽  
Microwave Absorption Properties ◽  
Phase Reduction ◽  
Transmission Electron

M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.

Microwave Absorption Properties of BaFe12O19 Prepared in Different Temperature with Polyaniline Nanocomposites

2017 ◽  
Vol 1142 ◽  
pp. 211-215 ◽  
Author(s):  
Wang Jun Feng ◽  
Xing Zhao ◽  
Wen Qian Zheng ◽  
Jun Tao Gang ◽  
Yue Cao ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Reflection Loss ◽  
In Situ Polymerization ◽  
Sol Gel ◽  
Ftir Spectra ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Result Show ◽  
Absorbing Material

The BaFe12O19 nanoparticles was prepared by sol-gel method in different temperature (750°C,850°Cand 950°C), and then BaFe12O19/polyaniline nanocomposites was synthesized by in situ polymerization. The XRD, FTIR spectra, SEM and vector network analyzer were used to analyze the "" chemical component, morphology and microwave absorption property of the nanocomposites. The result show that BaFe12O19 can be generated at 750°C without any impurity ,and its size increased with increase of calcination temperature.BaFe12O19 nanoparticle was coated with polyaniline partially, and we can get it have interaction with polyaniline through FTIR spectra. While the ferrite calcined at 850°C,the thickness of the absorbing material is 4.5mm,the nanocomposites have the largest reflection loss of-17.6 dB at 6 GHz,and its reflection loss values less than−10 dB in the range of 5-7.4GHz.

scholarly journals Microwave Absorption Properties of Magnetite Particles Extracted from Nickel Slag

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2162
Author(s):  
Pengze Yan ◽  
Yongqian Shen ◽  
Xueyan Du ◽  
Junkai Chong
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Microwave Absorption ◽  
Photoelectron Spectroscopy ◽  
Magnetic Loss ◽  
Interfacial Polarization ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
X Ray ◽  
Transmission Electron

The utilization of nickel slag has attracted much attention due to its high-content of valuable elements. As a part of these efforts, this work focuses on whether magnetite crystals, obtained from nickel slag via molten oxidation, magnetic separation, and ball-milling can be used as a microwave absorber. The composition, morphology, microstructure, magnetic properties, and microwave absorption performance were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and vector network analysis (VNA). The results reveal that the magnetite crystals exhibit excellent microwave absorption properties because of the synergistic action between dielectric loss and magnetic loss. The minimum reflection loss (RL) of the particles obtained after 6 h ball-milling reaches −34.0 dB at 16.72 GHz with thickness of 5 mm. The effective frequency bandwidth (RL ≤ −10 dB) is 4.8–5.4 GHz and 15.9–17.6 GHz. Interfacial polarization of the particles could play a crucial role in improving absorbing properties because several components contained in the particles can dissipate electromagnetic wave effectively. The current study could show great potential in the preparation of magnetite crystals and utilization of nickel slag.

Synthesis and Characterization Barium M-Hexaferrites (BaFe12-2xCoxMnxNixO19) as a Microwave Absorbent Material

2021 ◽  
Vol 317 ◽  
pp. 46-52
Author(s):  
Susilawati Hambali ◽  
Aris Doyan
Keyword(s):  
Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Band Frequency ◽  
Absorbent Material ◽  
Transmission Electron ◽  
X Band ◽  
Co Precipitation

This study aims to synthesize microwave absorbent material from barium M-Hexaferrite doped Co-Mn-Ni ions (BaFe12-2xCoxMnxNixO19) using co-precipitation method with varying concentrations (x = 0.2, 0.4, 0.6, 0.8, and 1.0) and calcinations temperatures in the range of 200 to 800°C. The samples characterization was conducted to investigate the effect of doping concentration variations on the electrical, magnetic and microwave absorption properties using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM-EDX), Transmission Electron Microscope (TEM), Vibrating Sample Magnetometer (VSM), and Network Vector Analyzer (VNA). The results from XRD characterization showed that the sample formed the barium iron oxide (BaFe12O19) phase with a = b = 5.03Å and c = 13.43Å. The results of SEM-EDX and TEM samples of BaFe9.6Co0.8Mn0.8Ni0.8O19 showed that the sample size ranged from 79-165 nm in the hexagonal crystal structure form. The magnetic properties with VSM indicate that the sample coercivity value decreases significantly from 0.41 T at x = 0.0 to 0.09 T at x = 0.8, indicating that the sample is soft magnetic. The value of electrical conductivity is in the range of 2.42 x 10-4 to 9.30 x 10-4 S/cm shows that the sample is a semiconductor. Analysis of the absorption properties of microwaves with VNA produced maximum permittivity and permeability values ​​of 28.40 and 54.40 at 10.30 GHz, and a maximum Reflection Loss (RL) value of -20.20 dB at a frequency of 15 GHz with an absorption coefficient of 99.05 % at concentration x = 0.6. The high permittivity, permeability, RL, and absorption coefficients indicate that the BaFe12-2xCoxMnxNixO19 sample has the potential to be a microwave absorbent material on X-band to Ku-band frequency.

scholarly journals Complex Permittivity and Microwave Absorption Properties of OPEFB Fiber–Polycaprolactone Composites Filled with Recycled Hematite (α-Fe2O3) Nanoparticles

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 918 ◽  
Author(s):  
Ebenezer Ekow Mensah ◽  
Zulkifly Abbas ◽  
Raba’ah Syahidah Azis ◽  
Nor Azowa Ibrahim ◽  
Ahmad Mamoun Khamis
Keyword(s):  
Microwave Absorption ◽  
Complex Permittivity ◽  
Microstructural Analysis ◽  
High Energy ◽  
Fe2o3 Nanoparticles ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Transmission Electron ◽  
Line Measurement

Recycled hematite (α-Fe2O3) nanoparticles with enhanced complex permittivity properties have been incorporated as a filler in a polycaprolactone (PCL) matrix reinforced with oil palm empty fruit bunch (OPEFB) fiber for microwave absorption applications. The complex permittivity values were improved by reducing the particle sizes to the nano scale via high-energy ball milling for 12 h. A total of 5–20 wt.% recycled α-Fe2O3/OPEFB/PCL nanocomposites were examined for their complex permittivity and microwave absorption properties via the open ended coaxial (OEC) technique and the transmission/reflection line measurement using a microstrip connected to a two-port vector network analyzer. The microstructural analysis of the samples included X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). At 1 GHz, the real (ε′) and imaginary (ε″) parts of complex permittivity of recycled α-Fe2O3 particles, respectively, increased from 7.88 to 12.75 and 0.14 to 0.40 when the particle size was reduced from 1.73 μm to 16.2 nm. A minimum reflection loss of −24.2 dB was achieved by the 20 wt.% nanocomposite at 2.4 GHz. Recycled α-Fe2O3 nanoparticles are effective fillers for microwave absorbing polymer-based composites in 1–4 GHz range applications.

scholarly journals Microwave Absorption Properties of Fe-SiO2 Nanocomposite Powder

2002 ◽  
Vol 66 (3) ◽  
pp. 135-138 ◽  
Author(s):  
Tadashi Fujieda ◽  
Shinzo Ikeda ◽  
Shuichi Suzuki ◽  
Teruyoshi Abe ◽  
Yasuhisa Aono
Keyword(s):  
Microwave Absorption ◽  
Nanocomposite Powder ◽  
Absorption Properties ◽  
Microwave Absorption Properties
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