Savithri. M. Nampoothiri; Viji. C; E. M. Mohammed; Robin Francis
Abstract
Nickel ferrite (NiFe₂O₄) nanoparticles were synthesized using sol-gel method and the powdered samples were sintered at 100°C and 200°C. X-ray Diffraction (XRD) patterns were used to determine the structure of nickel ferrite nanoparticles. Obtained the lattice parameter from the XRD data and ...
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Nickel ferrite (NiFe₂O₄) nanoparticles were synthesized using sol-gel method and the powdered samples were sintered at 100°C and 200°C. X-ray Diffraction (XRD) patterns were used to determine the structure of nickel ferrite nanoparticles. Obtained the lattice parameter from the XRD data and calculated the particle size using Debye- Sherrer formula. The details of the surface morphology of NiFe2O4 nanoparticles were studied by Scanning Electron Microscopic (SEM) analysis. The work aims at the investigation of the dielectric properties such as dielectric loss and permittivity of Nickel ferrite nanoparticles at various frequencies and temperatures. In addition, the ac conductivity of the nickel ferrite nanoparticles was studied.
Avanish Kumar Srivastava; Bhumika Samaria; Smita Soni; Anuj Shukla; Umesh Kumar
Abstract
In the present study, nano carbon (NC) was chemically functionalized by refluxing in nitric acid for 6 h to form acid functionalized NC (FNC). TEM, XRD, FTIR, Raman, N2 BET surface area and dc electrical conductivity characterizations confirm the functionalization and formation of surface oxygen functional ...
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In the present study, nano carbon (NC) was chemically functionalized by refluxing in nitric acid for 6 h to form acid functionalized NC (FNC). TEM, XRD, FTIR, Raman, N2 BET surface area and dc electrical conductivity characterizations confirm the functionalization and formation of surface oxygen functional groups, which in turn increase the hydrophilicity of FNC, thus rendering them solution processable. The basic framework of NC did not get change as confirmed from different characterization techniques. FNC were dispersed in an epoxy matrix by a solution blending method with different FNC loading levels (5, 7.0, 10, 12& 15 wt %). The FNC/epoxy composites were studied for electromagnetic properties in 8-12 GHz. Electromagnetic properties such as real and imaginary part of dielectric permittivity found increasing with increase of FNC loading. Reflection loss result of 10wt % of FNC composite shows RL >10 dB from 9.5 to12.0 GHz (absorption bandwidth~ 2.5 GHz) and effective absorption bandwidth (RL> 5dB) ~ 7 GHz (8-15 GHz). As a kind of potential microwave absorption material, the FNC composites are light weight and show excellent microwave absorbing ability. Copyright © VBRI Press.
G. T. Lamdhade; F. C. Raghuwanshi; R. M. Agrawal; V. M. Balkhande; T. Shripath
Abstract
The samples have been prepared in the form of pellets of SnO2 nanoparticles and synthesized via the liquid-phase co-precipitation technique. The ac electrical conductivity of samples is found to be frequency dependent. The dielectric constant increases with temperature and decreases with frequency of ...
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The samples have been prepared in the form of pellets of SnO2 nanoparticles and synthesized via the liquid-phase co-precipitation technique. The ac electrical conductivity of samples is found to be frequency dependent. The dielectric constant increases with temperature and decreases with frequency of applied field. The semiconducting behavior of SnO2 nanoparticles have been studied from I-V characteristics. The characterization of samples has been studied by XRD, FESEM, UV-spectra and TG-DTA plot
Satish Verma; Jagdish Chand;M. Singh
Abstract
Nanocrystalline Al3+ ions doped Mg0.2Mn0.5Ni0.3AlyFe2-yO4 compositions, where y=0.0, 0.05 and 0.10 have been synthesized by citrate precursor method. The X-ray diffraction (XRD) revealed that the ferrite has single phase cubic spinel structure. The calculated particle size from XRD data have been verified ...
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Nanocrystalline Al3+ ions doped Mg0.2Mn0.5Ni0.3AlyFe2-yO4 compositions, where y=0.0, 0.05 and 0.10 have been synthesized by citrate precursor method. The X-ray diffraction (XRD) revealed that the ferrite has single phase cubic spinel structure. The calculated particle size from XRD data have been verified using transmission electron microscopy (TEM). TEM photographs show that the ferrite powders consist of nanometer-sized particle. It was observed that the particle size decreases as the non-magnetic Al content increases. A decrease in lattice parameter and saturation magnetization with increase in aluminium concentration was attributed to smaller ionic radius and weakening of exchange interaction. Dependence of Mössbauer parameters such as isomer shift, quadrupole splitting and hyperfine magnetic field on Al 3+ ions concentration have been discussed. Initial permeability ‘µi’, relative loss factor (RLF), saturation magnetization and remanent magnetization decreases with increasing substitution of Al 3+ ions. The dielectric constant and dielectric loss decreases with increase in non magnetic Al 3+ ions. The dielectric constant follows the Maxwell–Wagner interfacial polarization. The electrical conduction in these ferrites is explained on the basis of the hopping mechanism.
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