ABSTRACT Effect of sintering temperature on the leakage current of polycrystalline multiferrioc DyFeO3 material is reported. Samples were synthesized through Sol-Gel route. From the Rietveld refinement of X-Ray Diffraction (XRD) data it... more
ABSTRACT Effect of sintering temperature on the leakage current of polycrystalline multiferrioc DyFeO3 material is reported. Samples were synthesized through Sol-Gel route. From the Rietveld refinement of X-Ray Diffraction (XRD) data it is observed that, samples were found to be of single phase. From the room temperature leakage current density study, it was observed that leakage current density decreases with increase of sintering temperature and Space charge limited conduction (SCLC) and Ohmic conduction mechanisms are dominant at lower and higher electric field values. The observations are corroborated in terms of microstructure changes with sintering temperature.
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The magneto-electric multiferroic hexaferrites have become very interesting due to their practical applications in multi-bit storage devices [1-2]. The XRD, Neutron, Magnetic and Mössbauer studies of magneto-electric Ba1−xSrxFe12O19... more
The magneto-electric multiferroic hexaferrites have become very interesting due to their practical applications in multi-bit storage devices [1-2]. The XRD, Neutron, Magnetic and Mössbauer studies of magneto-electric Ba1−xSrxFe12O19 (x=01@0.25) hexaferrites are reported. The samples are prepared through conventional solid state reaction method. The phase purity of the samples is confirmed through the XRD by using Rietveld refinement method and the lattice parameters are found to increase with increasing the Sr doping at Ba site. The neutron diffraction studies revealed the off-mirror-plane displacement of trigonal bipyramidal site. The bond angles, bond lengths and magnetic moments of the Fe sites are effected with Sr doping suggesting that the Sr doping at Ba site which is near to the trigonal bipyramidal site changes the structural properties of the crystal. The temperature dependent M-H loops are confirmed the hard magnetic nature. The saturation, remanent magnetisation and coerc...
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Abstract The present work reports the study of cation distribution in Ni substituted polycrystalline Ba0.5Sr1.5Co2Fe12O22 (Co2Y-BSCFO) hexaferrite samples using complimentary experimental methods viz., in-field F 57 e Mossbauer and Raman... more
Abstract The present work reports the study of cation distribution in Ni substituted polycrystalline Ba0.5Sr1.5Co2Fe12O22 (Co2Y-BSCFO) hexaferrite samples using complimentary experimental methods viz., in-field F 57 e Mossbauer and Raman spectroscopy. Combining the analysis of in-field F 57 e M o ¨ ssbauer and Raman spectroscopy measurements it is shown that the substituted Ni in Co2Y-BSCFO preferentially occupies the octahedral site with spin-down configuration i.e., 6cVI. The obtained cation distribution data is found to qualitatively match the magnetization values as obtained from bulk magnetic measurements. Temperature dependent dielectric data reveals a significant dispersion in dielectric constant associated with loss peaks and the conduction-hopping mechanism explains such behavior.
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The studies on the structural and magnetic properties of YFe1-xMnxO3 (x =0, 0.1, 0.2, 0.3, 0.4 and 0.5) multiferroic samples, prepared by sol-gel method, are reported in this paper. The X-ray diffraction studies confirm the crystalline... more
The studies on the structural and magnetic properties of YFe1-xMnxO3 (x =0, 0.1, 0.2, 0.3, 0.4 and 0.5) multiferroic samples, prepared by sol-gel method, are reported in this paper. The X-ray diffraction studies confirm the crystalline nature of the compounds which are formed in a pure single phase. From scanning electron micrographs, the average particle size is found to be increased with increasing Mn content and the sample is becoming porous. Magnetization versus magnetic field studies reveal that as Mn content increases, the saturation magnetization, remnant magnetization and coercive field values decreases which clearly indicates that the antiferromagnetic coupling gets strengthened. This increase in the antiferromagnetic nature is possibly due to the structural distortions in the compounds which give rise to the antiferromagnetic super exchange magnetic interactions between Fe+3 - Fe+3 and Fe+3 - Mn+3.
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Abstract Y1-xDyxFeO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) multiferroic materials are prepared by sol–gel method. The effect of Dy doping on the structural and magnetic properties of YFeO3 has been investigated in this paper. X-ray diffraction... more
Abstract Y1-xDyxFeO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) multiferroic materials are prepared by sol–gel method. The effect of Dy doping on the structural and magnetic properties of YFeO3 has been investigated in this paper. X-ray diffraction plots indicate that all the samples are crystalline and possess orthorhombic structure. The morphological studies show that samples possess non uniform grain size and grains are irregular in shape. Magnetic measurements suggest that substitution of Dy+3 ions in place of Y+3 ions effectively enhances the magnetization of YFeO3. This enhancement may be due to the additional Dy-Dy interactions, Dy-Fe interactions and Fe-O-Fe superexchange bond caused by the distortion of crystal structure.
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Research Interests:
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Abstract To meet the industrial requirements of light weight and high strength materials, lot of research work is going on worldwide for improvement of properties of light weight non-metallic composites. Researchers are trying to meet the... more
Abstract To meet the industrial requirements of light weight and high strength materials, lot of research work is going on worldwide for improvement of properties of light weight non-metallic composites. Researchers are trying to meet the industrial requirements by adding nanoparticles in preparation of composite materials and making nanocomposites. Nanocomposites are formed by mixing two or more dissimilar materials and adding nanoparticles in the matrix in order to control and develop new and improved properties of composites. The properties of composites depend not only upon the individual components used but also upon the morphology and the interfacial characteristics of the constituents and nanoparticles added. In the present investigation, laminates of epoxy resin and nanoparticles of Al2O3 as filler are used with Aramid fibre, hybrid of Carbon and Aramid fibre as reinforcement are prepared. The nanoparticles, in the proportion of 1%, 3% and 5% are loaded into the composites. Nanoparticles of Al2O3 of 20-30nm size are first dispersed into methanol by mechanical stirring. The solution is further sonicated for effective dispersion of nanoparticles. The mixture of methanol and Al2O3 nanoparticles are mixed in Epoxy resin and mechanically stirred and sonicated. During mixing some of the methanol is evaporated. Further, the remaining methanol is removed by heating and drying. Then, Hardener is mixed with the mixture of epoxy- Al2O3 and laminates are prepared. The laminates are cut to the required size of test samples for testing mechanical properties. It is observed that the mechanical properties are improved with the addition of nanoparticles of Al2O3. The SEM images of nanocomposites formed with 5% nanoparticle loading with Plane composites, Aramid, Carbon, hybrid of Aramid and Carbon composites shows that good bonding is formed between the fibre and resin mixed with nanoparticles.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Effect of sintering temperature on the leakage current of polycrystalline multiferrioc DyFeO3 material is reported. Samples were synthesized through Sol-Gel route. From the Rietveld refinement of X-Ray Diffraction (XRD) data it... more
ABSTRACT Effect of sintering temperature on the leakage current of polycrystalline multiferrioc DyFeO3 material is reported. Samples were synthesized through Sol-Gel route. From the Rietveld refinement of X-Ray Diffraction (XRD) data it is observed that, samples were found to be of single phase. From the room temperature leakage current density study, it was observed that leakage current density decreases with increase of sintering temperature and Space charge limited conduction (SCLC) and Ohmic conduction mechanisms are dominant at lower and higher electric field values. The observations are corroborated in terms of microstructure changes with sintering temperature.
Research Interests:
The magneto-electric multiferroic hexaferrites have become very interesting due to their practical applications in multi-bit storage devices [1-2]. The XRD, Neutron, Magnetic and Mössbauer studies of magneto-electric Ba1−xSrxFe12O19... more
The magneto-electric multiferroic hexaferrites have become very interesting due to their practical applications in multi-bit storage devices [1-2]. The XRD, Neutron, Magnetic and Mössbauer studies of magneto-electric Ba1−xSrxFe12O19 (x=01@0.25) hexaferrites are reported. The samples are prepared through conventional solid state reaction method. The phase purity of the samples is confirmed through the XRD by using Rietveld refinement method and the lattice parameters are found to increase with increasing the Sr doping at Ba site. The neutron diffraction studies revealed the off-mirror-plane displacement of trigonal bipyramidal site. The bond angles, bond lengths and magnetic moments of the Fe sites are effected with Sr doping suggesting that the Sr doping at Ba site which is near to the trigonal bipyramidal site changes the structural properties of the crystal. The temperature dependent M-H loops are confirmed the hard magnetic nature. The saturation, remanent magnetisation and coerc...
Research Interests:
Abstract The present work reports the study of cation distribution in Ni substituted polycrystalline Ba0.5Sr1.5Co2Fe12O22 (Co2Y-BSCFO) hexaferrite samples using complimentary experimental methods viz., in-field F 57 e Mossbauer and Raman... more
Abstract The present work reports the study of cation distribution in Ni substituted polycrystalline Ba0.5Sr1.5Co2Fe12O22 (Co2Y-BSCFO) hexaferrite samples using complimentary experimental methods viz., in-field F 57 e Mossbauer and Raman spectroscopy. Combining the analysis of in-field F 57 e M o ¨ ssbauer and Raman spectroscopy measurements it is shown that the substituted Ni in Co2Y-BSCFO preferentially occupies the octahedral site with spin-down configuration i.e., 6cVI. The obtained cation distribution data is found to qualitatively match the magnetization values as obtained from bulk magnetic measurements. Temperature dependent dielectric data reveals a significant dispersion in dielectric constant associated with loss peaks and the conduction-hopping mechanism explains such behavior.
Research Interests:
The studies on the structural and magnetic properties of YFe1-xMnxO3 (x =0, 0.1, 0.2, 0.3, 0.4 and 0.5) multiferroic samples, prepared by sol-gel method, are reported in this paper. The X-ray diffraction studies confirm the crystalline... more
The studies on the structural and magnetic properties of YFe1-xMnxO3 (x =0, 0.1, 0.2, 0.3, 0.4 and 0.5) multiferroic samples, prepared by sol-gel method, are reported in this paper. The X-ray diffraction studies confirm the crystalline nature of the compounds which are formed in a pure single phase. From scanning electron micrographs, the average particle size is found to be increased with increasing Mn content and the sample is becoming porous. Magnetization versus magnetic field studies reveal that as Mn content increases, the saturation magnetization, remnant magnetization and coercive field values decreases which clearly indicates that the antiferromagnetic coupling gets strengthened. This increase in the antiferromagnetic nature is possibly due to the structural distortions in the compounds which give rise to the antiferromagnetic super exchange magnetic interactions between Fe+3 - Fe+3 and Fe+3 - Mn+3.
Research Interests:
Abstract Y1-xDyxFeO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) multiferroic materials are prepared by sol–gel method. The effect of Dy doping on the structural and magnetic properties of YFeO3 has been investigated in this paper. X-ray diffraction... more
Abstract Y1-xDyxFeO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) multiferroic materials are prepared by sol–gel method. The effect of Dy doping on the structural and magnetic properties of YFeO3 has been investigated in this paper. X-ray diffraction plots indicate that all the samples are crystalline and possess orthorhombic structure. The morphological studies show that samples possess non uniform grain size and grains are irregular in shape. Magnetic measurements suggest that substitution of Dy+3 ions in place of Y+3 ions effectively enhances the magnetization of YFeO3. This enhancement may be due to the additional Dy-Dy interactions, Dy-Fe interactions and Fe-O-Fe superexchange bond caused by the distortion of crystal structure.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Abstract To meet the industrial requirements of light weight and high strength materials, lot of research work is going on worldwide for improvement of properties of light weight non-metallic composites. Researchers are trying to meet the... more
Abstract To meet the industrial requirements of light weight and high strength materials, lot of research work is going on worldwide for improvement of properties of light weight non-metallic composites. Researchers are trying to meet the industrial requirements by adding nanoparticles in preparation of composite materials and making nanocomposites. Nanocomposites are formed by mixing two or more dissimilar materials and adding nanoparticles in the matrix in order to control and develop new and improved properties of composites. The properties of composites depend not only upon the individual components used but also upon the morphology and the interfacial characteristics of the constituents and nanoparticles added. In the present investigation, laminates of epoxy resin and nanoparticles of Al2O3 as filler are used with Aramid fibre, hybrid of Carbon and Aramid fibre as reinforcement are prepared. The nanoparticles, in the proportion of 1%, 3% and 5% are loaded into the composites. Nanoparticles of Al2O3 of 20-30nm size are first dispersed into methanol by mechanical stirring. The solution is further sonicated for effective dispersion of nanoparticles. The mixture of methanol and Al2O3 nanoparticles are mixed in Epoxy resin and mechanically stirred and sonicated. During mixing some of the methanol is evaporated. Further, the remaining methanol is removed by heating and drying. Then, Hardener is mixed with the mixture of epoxy- Al2O3 and laminates are prepared. The laminates are cut to the required size of test samples for testing mechanical properties. It is observed that the mechanical properties are improved with the addition of nanoparticles of Al2O3. The SEM images of nanocomposites formed with 5% nanoparticle loading with Plane composites, Aramid, Carbon, hybrid of Aramid and Carbon composites shows that good bonding is formed between the fibre and resin mixed with nanoparticles.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Abstract The nanosize effects on magnetic field induced transitions in La 0.67− x Eu x Ca 0.33 MnO 3 ( x =0.25 and 0.27) system are presented in this paper. The reduction in the particle size of the system shows drastic effects on the... more
Abstract The nanosize effects on magnetic field induced transitions in La 0.67− x Eu x Ca 0.33 MnO 3 ( x =0.25 and 0.27) system are presented in this paper. The reduction in the particle size of the system shows drastic effects on the electrical transport properties leading to robustness of the charge ordering phenomenon. The metal–insulator transition found in bulk materials at low magnetic fields disappeared in nanoparticles of the same material and a high field induced metal–insulator transition emerged at lower temperatures. These results manifest a strong correlation between the chemical pressures induced by doping of various ions at A-site and nanosize related phenomenon.
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ABSTRACT: A facile and highly efficient method for the synthesis of 4-Iodo quinolines in good to excellent yields by using inexpensive chemicals to reduce the cost. The present work describes the synthesis of highly substituted and noval... more
ABSTRACT: A facile and highly efficient method for the synthesis of 4-Iodo quinolines in good to excellent yields by using inexpensive chemicals to reduce the cost. The present work describes the synthesis of highly substituted and noval 4-iodoquinolines involves the ...
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Abstract Structural, magnetic and 57Fe Mossbauer investigations of indium (In) doped cobalt ferrite are reported. Polycrystalline CoFe2−xInxO4, x = 0, 0.2, 0.4, 0.6, 0.8 samples are prepared by sol–gel method. In contrast to most of the... more
Abstract Structural, magnetic and 57Fe Mossbauer investigations of indium (In) doped cobalt ferrite are reported. Polycrystalline CoFe2−xInxO4, x = 0, 0.2, 0.4, 0.6, 0.8 samples are prepared by sol–gel method. In contrast to most of the literature, in the present work phase pure samples are obtained, except for x = 0.2. The presence of ferrimagnetic ordering in all the samples is confirmed from in-field 57Fe Mossbauer spectroscopy measurements. The cation distribution is obtained unambiguously from the combined analysis of Raman and in-field 57Fe Mossbauer spectroscopy measurements. The variation of magnetic moment values calculated from the obtained cation distribution are found to match qualitatively with the experimental values, supporting the analysis of in-field 57Fe Mossbauer and Raman spectroscopy measurements.