Browsing by Author "Jayaprakash, R"

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    EFFECT OF CONCENTRATION ON DIELECTRIC PROPERTIES OF CO-CU FERRITE NANO PARTICLES
    (Elsevier B.V, 2013) Balavijayalakshmi, J; Suriyanarayanan, N; Jayaprakash, R; Gopalakrishnan, V
    Nano-sized Cobalt ferrites doped with copper as an additive element CoxCu(1-x)Fe2O4 (where x =0,0.2,0.4,0.6,0.8,1) are synthesized using co-precipitation method. Cobalt-Copper ferrite samples sintered at 600○C are subjected to X-ray diffraction to calculate the average particle size and lattice parameters using Debye – Scherrer formula. The FT-IR spectra of these samples are recorded to ensure the presence of the metallic compounds. The variations of dielectric constant and dielectric loss for all the samples are studied as a function of frequency. The crystalline structure of composite nano particles are characterized by Transmission Electron Microscope (TEM).
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    EFFECT OF CONCENTRATION ON DIELECTRIC PROPERTIES OF CO-CU FERRITE NANO PARTICLES
    (Elsevier, 2013) Balavijayalakshmi, J; Suriyanarayanan, N; Jayaprakash, R; Gopalakrishnan, V
    Nano-sized Cobalt ferrites doped with copper as an additive element CoxCu(1-x)Fe2O4 (where x =0,0.2,0.4,0.6,0.8,1) are synthesized using co-precipitation method. Cobalt-Copper ferrite samples sintered at 600○C are subjected to X-ray diffraction to calculate the average particle size and lattice parameters using Debye – Scherrer formula. The FT-IR spectra of these samples are recorded to ensure the presence of the metallic compounds. The variations of dielectric constant and dielectric loss for all the samples are studied as a function of frequency. The crystalline structure of composite nano particles are characterized by Transmission Electron Microscope (TEM).
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    EFFECT OF PARTICLE SIZE ON OPTICAL AND ELECTRICAL PROPERTIES IN MIXED CDS AND NIS NANOPARTICLES SYNTHESIS BY ULTRASONIC WAVE IRRADIATION METHOD
    (Elsevier, 2016-12) Mohanraj, V; Jayaprakash, R; Robert, R; Balavijayalakshmi, J; Gopi, S
    The mixed phase CdS and NiS nanoparticles are prepared by adopting ultrasonic wave irradiation method under different doping concentration of Ni in CdS. The well defined nano spheres are obtained during this synthesis process. The predicted particle sizes from X-ray diffraction (XRD) analysis are found to lie in the range between 37 and 49 nm. The effective doping of Ni lead to form the mixture of two phases such as CdS and NiS. The respective change due to the formation of mixture of CdS and NiS is reflected well in the band gap energy which is measured in Diffused Reflectance Spectra (DRS). It is predicted in the range of 2.41–2.23 eV respectively. Consistency of particle size with XRD are confirmed from Transmission Electron Microscope (TEM) images and also identified the presence of Nickel Sulfide and Cadmium Sulfide in nanostate with average particle size as 54 nm. The Energy Dispersive X-ray (EDAX) analysis confirmed the existence of Ni, Cd and S the doping levels. The optical absorption analysis of samples are performed in UV–vis range 400–600 nm. The synthesized samples are further characterized Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric (TGA) analysis, I-V characteristic and conductivity measurements.
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    EFFECTS OF SINTERING ON STRUCTURAL AND MAGNETIC PROPERTIES OF CU SUBSTITUTED COBALT–NICKEL MIXED FERRITE NANO PARTICLES
    (Elsevier, 2014-08) Balavijayalakshmi, J; Suriyanarayanan, N; Jayaprakash, R
    Copper substituted cobalt–nickel mixed ferrite nano particles are synthesized by co-precipitation method and the samples are sintered at 130 °C, 600 °C and 900 °C. The effects of sintering on structural and magnetic properties are studied using XRD analysis and VSM studies. The particle sizes are found to be 12 nm and 32 nm for the samples sintered at 600° and 900 °C respectively and the degree of crystallinity of the sample increases with increasing sintering temperature. The absorption bands shift to lower values on sintering the samples. The saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) increase on sintering the samples at 600 °C and 900 °C. EDX results confirm the presence of Co, Ni, Cu, Fe and O without any impurities.
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    ROLE OF COPPER ON STRUCTURAL, MAGNETIC AND DIELECTRIC PROPERTIES OF NICKEL FERRITE NANO PARTICLES
    (Elsevier, 2015-07) Balavijayalakshmi, J; Suriyanarayanan, N; Jayaprakash, R
    Copper doped nickel ferrites Ni(1−x)CuxFe2O4 (where x=0.2, 0.4, 0.6) nanoparticles are prepared by co-precipitation method and sintered at 600 °C. The XRD study confirms the formation of single-phase cubic spinel Ni–Cu ferrites. The particle size increases with Cu substitution. FT-IR spectra confirm the absorption bands around 554–547 cm−1 for the tetrahedral sites and around 448–450 cm−1 for the octahedral sites. The inclusion of copper shifts the tetrahedral band to lower values. The saturation magnetization (Ms) and remanent magnetization (Mr) decrease with increase in copper concentration and the coercivity (Hc) is found to increase for all the compositions sintered at 600 °C. The dielectric constant decreases drastically for all the compositions and reaches a constant value. These nanoparticles can be tested for humidity sensing applications.