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Your search keyword '"Padmamalini, N."' showing total 12 results
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12 results on '"Padmamalini, N."'

11. Structural, and magnetic studies of a novel homemade spray pyrolysis synthesized Fe-doped CeO2thin films

Author

Raja, S. Philip, Suresh, S., Padmamalini, N., Manimekalai, K., and Venkateswaran, C.

Abstract

Thin film samples of pure CeO2and Fe-doped CeO2were prepared via a homemade spray pyrolysis set-up with an aim to explore its suitability for use as functional materials in spintronics applications. Compressed air was used as a carrier gas to spray deposit the films on preheated glass substrate at an optimum temperature of 400 °C. Structural analysis using X-ray diffraction confirm the single-phase formation of CeO2for pure and Fe-doped samples. Field emission electron microscope images illustrate the fairly uniform deposition of thin films with nanocrystalline nature. Energy dispersive X-ray analysis confirm the near stoichiometry of doped Ce1-xFexO2(x = 0, 0.05, 0.1) samples. Magnetic behavior of the samples were studied using Vibrating Sample Magnetometer which show a dominant diamagnetic behavior for both Fe-doped and pure CeO2thin films. Insufficient number of oxygen vacancies produced during the deposition of thin films is expected to the cause for the absence of ferromagnetic ordering at room temperature.

Published
2023
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12. Structural, dielectric and impedance studies on high-k ZrO-TiO nanocomposite.

Author

Padmamalini, N. and Ambujam, K.

Subjects
ZIRCONIUM oxide, CHEMICAL synthesis, DIELECTRIC properties of nanocomposite materials, SYNTHESIS of Nanocomposite materials, COPRECIPITATION (Chemistry), CALCINATION (Heat treatment), X-ray diffraction
Abstract

High-k dielectric ZrO-TiO nanocomposite was prepared using a simple Coprecipitation-calcination technique. X-ray diffraction shows that the synthesized nanocomposite showed monoclinic structure for ZrO and orthorhombic structure for TiO. The SEM and TEM images show an average particle size of 20-30 nm. The dielectric properties of ZrO-TiO nanoparticles were studied in the frequency range of 50 Hz-5 MHz at different temperatures. The dielectric constant and dielectric loss is found to decrease with an increase in the frequency at different temperatures. The dielectric properties of ZrO-TiO nanoparticles are found to be significantly enhanced specially in the low frequency range due to confinement. The dielectric constant was found to greater than that of nano zirconia. The AC electrical conductivity measurements reveal that the conduction depends on both the frequency and the temperatures. Nyquist plots indicated the presence of a non-Debye relaxation. The determined relaxation times followed Arrhenius law and the activation energy for relaxation was found to be 0.178 eV. [ABSTRACT FROM AUTHOR]

Published
2017
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