The scope of the present work is in enhancing the particle size, and dielectric properties of Mg-substituted Cobalt ferrites nanoparticles prepared by sol–gel auto combustion method. The different ratios of Mg-substituted Co Ferrites (Co[Formula: see text]MgxFe2O4([Formula: see text], 0.05, 0.10, 0.15, 0.20 and 0.30)) are calcinated at 850[Formula: see text]C. The synthesized nanoparticles were characterized by powder XRD, FTIR, FE-SEM, EDX techniques and dielectric behavior. The structural parameters were confirmed from powder XRD and the average particle size is obtained from 39 to 67 nm due to the substitution of Mg[Formula: see text] which was calculated by Debye Scherrer’s formula. FE-SEM showed the surface morphology of the different ratio of the sample. The dielectric loss has measured the frequency range of 50[Formula: see text]Hz–5[Formula: see text]MHz. From electrical modulus, conductivity relaxation and thermal activation of charge carriers has been discussed.

Ruban Kumar A

Department of Physics

School of Advanced Sciences

Vellore Campus

Gowreesan S

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Preparation of Magnesium-Based Cobalt-Ferrites (Co1−xMgxFe2O4) Nanoparticles by Sol–Gel Auto Combustion Method

International Journal of Nanoscience

In this work, we have prepared Mg substituted CoFe2O4 from the transition metals by Sol–Gel Auto combustion method for different concentration (0.00, 0.05, 0.10, 0.15, 0.20 and 0.30) the aqueous materials involved Cobalt Nitrate, Magnesium Nitrate, Ferric nitrate and used a citric acid as a fuel. The final product was calcinated at 850&nbsp;°C. Powder XRD studies confirmed the crystal structure, FTIR revealed the presence of various functional groups, FE-SEM showed the morphology of the prepared sample. EDAX shows percentage of chemical composition in series of Co ferrites. Dielectric constant, AC Conductivity, Cole–Cole plots, Activation Energy were analysed for the prepared nanoparticles for various frequencies at different temperatures. The dielectric constant values are higher for Mg substituted CoFe2O4. The activation energies were also calculated which ranged from 0.1552 to 0.1753&nbsp;eV for CoFe2O4 and Co1−xMgxFe2O4 materials. © 2016, Springer Science+Business Media New York.

Journal of Materials Science: Materials in Electronics

Effects of Mg2+ ion substitution on the structural and electric studies of spinel structure of Co1−xMgxFe2O4

In this present study, we have reported the synthesis of ZnMn2O4, transitional metal oxide by sol–gel method. The structural and morphological properties are confirmed using various characterization techniques namely XRD, FT-IR and SEM with EDX. Dielectric studies of ZnMn2O4 are measured at the frequency varying from 50&nbsp;Hz to 5&nbsp;MHz for the temperature range of 303–573&nbsp;K. The temperature dependent electrical parameters like impedance and modulus exhibit a strong correlation with the grains, grain boundaries and space charge effects in the synthesized material. Diffusion of oxygen vacancies in the dipoles and defects in the material due to oxygen vacancy complexes are investigated by the activation energy obtained from Arrhenius plot. It was found that the relaxation process was dominated by the hopping mechanism between the Mn3+ and Mn4+. Nyquist plot of impedance was attributed to the existence of space charge interface, grain boundary and grain conduction mechanism of the material. © 2016, Springer Science+Business Media New York.

Investigation of structural and electrical properties of ZnMn2O4 synthesized by sol–gel method

In this work, spinel FeCo2O4 is synthesized by sol-gel method using succinic acid as a chelating agent at 900 °C. The structural, spectroscopic and morphological characterization was carried out by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy equipped with Energy Dispersive X-ray spectrometer (SEM-EDX). The M-H loop at room temperature confirms the ferromagnetic property of the sample. The frequency and temperature dependence of dielectric constant (ε) and dielectric loss (tan δ) shows the presence of Maxwell-Wagner relaxation in the sample due to the presence of oxygen vacancy. Nyquist plot for frequency and temperature domain signifies the presence of grain effect, grain boundary effect and electrode interface in the conduction process. Electric modulus under suppression of electrode polarization shows the grain and grain boundary effects. The electrode polarization is observed in the lower frequency range of the conductivity graph. © 2015 Elsevier Ltd. All rights reserved.

Journal	International Journal of Nanoscience
Publisher	World Scientific Pub Co Pte Lt
ISSN	0219-581X
Open Access	No