International Conference

Permanent URI for this collectionhttps://dspace.psgrkcw.com/handle/123456789/41

Browse

Now showing 1 - 20 of 81

SYNTHESIS AND STUDY OF MAGNETIC PROPERTIES OF NANO CRYSTALLINE ZN-CU MIXED FERRITES
(Narosa Publishing house / PSGR Krishnammal College for Women, 2008-12-18) Balavijayalakshmi J; Jayaprakash R; Suriya Narayanan N; Marutha Senthil S; Govindaraj G; Singh VN; Phani A R
Magnetic nanoparticles of spinel ferrites are of great interest in fundamental science, especially for addressing the fundamental relationships between magnetic properties and their crystal chemistry and structure. Spinel ferrites have been investigated in recent years for their useful electrical and magnetic properties due to the wide applications in information storage systems, magnetic bulk cores, magnetic fluids microwave absorbers and magnetic diagnostics. The synthesis, structural characterization and magnetic properties of spinel nano ferrites have been investigated with much interest. Zn-Cu mixed ferrites are prepared by co-precipitation method. Zn-Cu mixed ferrites as prepared and sintered are subjected to X-ray diffraction (XRD) using Cu Kα radiation to confirm the particle size. The consistency of Nano size of the particle is analyzed using TEM micrograph. The FT-IR spectrum of the sample is recorded at different sintering temperatures. The magnetic measurements of Zn-Cu mixed ferrites are carried out using vibrating sample magnetometer.
SYNTHESIS AND CHARACTERIZATION OF NANO – CRYATALLINE CO-CU MIXED FERRITES
(SRM University, Chennai, 2010-02-24) Balavijayalakshmi J; Suriya Narayanan N; Jayaprakash R; Gopalakrishnan V; Sanjay Kumar; Singh VN; Phani A R
Nano-crystalline Cobalt ferrite doped with copper as an additive element Co0.8Cu0..2Fe2O4 is synthesized using co-precipitation method. Cobaltous Chloride [CoCl2.6H2O], Cupric Chloride [CuCl2.2H2O], anhydrous Ferric Chloride [FeCl3] along with sodium hydroxide [NaOH] is used as raw materials. Cobalt-Copper ferrite sample sintered at 600○C are subjected to X-ray diffraction to calculate the average nano-crystalline size using Debye – Scherrer formula. The FT-IR spectra of the sample are recorded to ensure the presence of the metallic compounds. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM).
PREPARATION OF COBALT-COPPER FERRITE (CO0.8CU0.2FE2O4) NANOPOWDER VIA COPRECIPITATION METHOD AND INVESTIGATION OF ITS MAGNETIC PROPERTIES
(K.S.Rangasamy College of Technology, Tiruchengode, Namakkal, Tamilnadu, 2012-11-21) Balavijayalakshmi J; Suriya Narayanan N; Jayaprakash R
Copper substituted Cobalt ferrite nano particles (Co0.8Cu0.2Fe2O4) are synthesized using co-precipitation method. Cobaltous Chloride [CoCl2.6H2O], Cupric Chloride [CuCl2.2H2O] and anhydrous Ferric Chloride [FeCl3] along with sodium hydroxide [NaOH] are used as the raw materials. Cobalt-Copper ferrite sample sintered at 900○C is subjected to X-ray diffraction to calculate the average nano-crystallite size using Debye – Scherrer formula. The FT-IR spectra of the samples are recorded to ensure the presence of metallic compounds. The magnetic properties of the copper doped cobalt ferrite nano particles are studied using Vibrating Sample Magnetometer (VSM). The morphological analysis of the sample is done using SEM.
GROWTH OF CE ADDED NBT-BT SINGLE CRYSTAL BY FLUX METHOD AND ITS CHARACTERIZATION
(AIP, 2013) S, Shanmuga Sundari; R, Dhanasekaran
The ferroelectric properties and piezoelectric properties are enhanced by the addition of CeO2. CeO2 in the 0.94Na0.5Bi0.5TiO3−0.06BaTiO3 (NBT-BT). 0.4 wt% of CeO2. CeO2 added NBT-BT crystals were grown by flux method.X-ray diffraction studies show that the Ce ion diffuses into the NBT-BT lattice to form a solid solution. Temperature dependence of dielectric constant for the frequency range 20 Hz-2 MHz is studied. Due to the addition of CeO2 the dielectric loss is found to be 1.1 for 1kHz. The diffuseness parameter is found to be 1.82.
STRUCTURAL, DIELECTRIC, PIEZOELECTRIC AND FERROELECTRIC CHARACTERIZATION OF NBT-BT LEAD-FREE PIEZOELECTRIC CERAMICS
(IOP Sciences, 2013) S, Shanmuga Sundari; Binay Kumar; R, Dhanasekaran
Lead free piezoelectric 0.94(Na0.5Bi0.5)TiO3-0.06BaTiO3 (NBT-BT) ceramics were synthesized in MPB composition by conventional solid state reaction method. The crystalline nature of NBT-BT ceramic was studied by XRD and the size of the grains are determined by SEM. The X- ray diffraction results reveal that Ba2+ diffuse into the Na0.5 Bi0.5TiO3 lattices to form a solid solution with a pure perovskite structure. Because of the strong ferroelectricity and MPB, the ceramics exhibit high piezoelectric properties: d33 = 206 pC/N. Td (depolarization temperature) and Tm (temperature at with the dielectric constant r reaches a maximum) were observed through the phase transition in dielectric studies. In addition, the prepared ceramic exhibits relaxor characteristic, which probably results from the cation disordering in the 12fold coordination sites. Pr and Ec of the prepared ceramics were determined from the P-E hysteresis loop.
PURE AND ND ADDED NBT-BT SINGLE CRYSTALS-GROWTH AND THEIR CHARACTERIZATION
(AIP, 2014) S, Shanmuga Sundari; K, Baskar; R, Dhanasekaran
The lead free piezoelectric materials are secured an important place in the field of material science and engineering. In the present work single crystals of sodium bismuth titanate- barium titanate (0.94NBT-0.06BT) and 0.6 wt % of Nd added NBT-BT has been grown by flux method. The addition of 0.6 wt% of Nd shows the inhomogeneity in melt and the crystals collected from the top, middle and bottom portions of the crucible have been characterized for their structural and dielectric properties. The Nd concentration is found to be more in the crystals grown from the bottom portion of crucible and it was confirmed by optical and structural analysis. After the addition of Nd the color of the crystal changes form pale yellow to muddy green. The depolarization temperature (Td) and the temperature where the dielectric constant reaches its maximum (Tm) are increased from 442 K to 475 K and 595 K and 628 K respectively after the addition the of Nd in NBT-BT.
COMBUSTION SYNTHESIS OF NOVEL CATHODE MATERIAL OF KMNPO4 FOR SUPERCAPACITORS
(CSIR –National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram, 2014-02-19) N, Priyadharsini; R, Kalai Selvan
KMnPO4 has prepared as a unique supercapacitor material because of the extensive electrochemical properties of LiMnPO4, which is proved as a one of the best cathode materials1. The compound was synthesized via combustion synthesis using potassium acetate, manganese acetate and ammonium dihydrogen phosphate as precursors with a fuel of citric acid. Structural, surface morphology were studied by XRD, FTIR and TEM analysis and the sample encompass the structure of triclinic having the space group of P (2). The electrochemical properties were observed using cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy in a three electrode system at a potential range from -0.6 to 0.6 V vs Hg/HgO. The variation in the electrochemical performance of the sample was studied in three different electrolytes such as 1M LiOH, 1M KOH and 1M NaOH. The result shows that KMnPO4 exhibits higher capacitance of 335 F/g at a scan rate of 2mVs-1 for 1M NaOH. This material shows good specific capacity; replace with all the available Li based Manganese pseudocapacitors which are already proved their recital.
HYDROTHERMAL SYNTHESIS OF MN DOPED TIO2 NANO PARTICLES FOR DILUTE MAGNETIC SEMICONDUCTORS
(Vellore Institute of Technology, Vellore, 2014-03-10) N, Priyadharsini; A, Nancy
The TiO2 nano particles are synthesized of Manganese doping through a novel hydrothermal method. The undoped and doped nanostructures were systematically investigated employing X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and Fourier transform infrared (FTIR) analysis. The space group of the material and associated lattice parameters was ascertained through XRD analysis. The Energy Dispersive Spectroscopy analysis gives the proportion of the chemical composition of the sample synthesized with and without Mn doping. The magnetic properties of the compound are measured through Vibration sample magnetometer (VSM). It is observed that the ferromagnetic behavior of the compound improved largely due to the replacement of Mn ions with Ti. This enhanced ferromagnetic property of the material will be functional for the dilute magnetic semiconductors (DMS). From these observed results, room temperature ferromagnetism behavior can be explained by polaron formation of charge carriers
INVESTIGATION ON STRUCTURAL AND MAGNETIC PROPERTIES OF COBALT DOPED MAGNESIUM FERRITE NANOPARTICLES
(SRM University, Kattankulathur, Chennai, 2015-02-04) Balavijayalakshmi J; Sudha T; Karthika K
Nanosized spinel ferrites have attracted considerable attention for their interesting structural, magnetic and electrical properties. The physical and chemical properties of nanomaterials have been enhanced because of their surface-to-volume ratio. To search for new good gas-sensing materials and the new properties of conventional materials has become an active research field. Magnesium ferrite is a most versatile ferrite, due to its high resistivity and low eddy currents. Also the technological importance of cobalt ferrite has motivated several studies on the synthesis as well as the physical properties of this material. Hence an attempt is made to synthesize cobalt doped magnesium ferrite nanoparticles (Mg0.6Co0.4Fe2O4) by co-precipitation method. Magnesium chloride [MgCl2. 6H2O], Cobaltous Chloride [CoCl2.6H2O], anhydrous Ferric Chloride [FeCl3] along with sodium hydroxide [NaOH] is used as raw materials. Magnesium-Cobalt ferrite sample annealed at 600○C are subjected to X-ray diffraction to calculate the average nano-crystalline size using Debye – Scherrer formula. The FT-IR spectra of the sample are recorded to ensure the presence of the metallic compounds. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM). The magnetic properties of the cobalt doped magnesium ferrite nano particles are studied using Vibrating Sample Magnetometer (VSM).
SYNTHESIS AND CHARACTERIZATION OF CUPRIC CHLORIDE DOPED ZINC SULPHIDE NANOPARTICLES
(SRM University, Kattankulathur, Chennai, 2015-02-04) Balavijayalakshmi J; Manju S; Lavanya S
In recent years, the research on semiconductor nanoparticles has stimulated much interest because of their unique optical and electrical properties. The nanosized semiconductor crystallites could produce optical properties which are different from bulk materials. Among the semiconductor nanoparticles, Zinc Sulphide is an important II–VI semiconductor material researched extensively because of its wide range of applications in electroluminescence devices, phosphors, light emitting displays and optical sensors. Semiconductor nanoparticles doped with transition metal ions have attracted much attention because of their luminescent properties. Hence an attempt is made to synthesize cupric chloride doped zinc sulphide nanoparticles. The synthesized nanoparticles are subjected to X-ray diffraction to calculate the average nano-crystalline size using Debye – Scherrer formula. The optical properties of the samples are studied using UV-Vis Spectroscopy. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM). FT-IR spectroscopy is used to determine the chemical bonding in the synthesized sample.
EFFECTS OF ANNEALING ON STRUCTURAL AND MAGNETIC PROPERTIES OF COBALT DOPED MAGNESIUM FERRITE NANOPARTICLES
(PSG IAS, Coimbatore, 2015-08-07) Balavijayalakshmi J; Sudha T
Nano-structured materials are now being studied intensively due to their novel physicochemical properties. Applications of gas sensors have been growing at a consistent pace in the recent years. The mixed-metal oxide gas sensors offer advantages over other gas sensors devices due to their simple implementation, low cost and good reliability for real time control systems. To search for new good gas-sensing materials and the new properties of conventional materials has become an active research field. Among different ferrites, magnesium ferrite enjoys a special attention because of its vast applications in high density recording media, heterogeneous catalysis, adsorption, sensors and magnetic technologies. Also the technological importance of cobalt ferrite has motivated several studies on the synthesis as well as the physical properties of this material. Hence an attempt is made to synthesize cobalt doped magnesium ferrite nanoparticles by co-precipitation method. Magnesium chloride [MgCl2. 6H2O], Cobaltous Chloride [CoCl2.6H2O], anhydrous Ferric Chloride [FeCl3] along with sodium hydroxide [NaOH] is used as raw materials. Magnesium-Cobalt ferrite sample annealed at 130○C, 600○C and 900○C are subjected to X-ray diffraction to calculate the average nano-crystalline size using Debye – Scherrer formula. The FT-IR spectra of the samples are recorded to ensure the presence of the metallic compounds. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM). The magnetic properties of the cobalt doped magnesium ferrite nano particles are studied using Vibrating Sample Magnetometer (VSM). These samples can be tested for gas sensing applications.
CHARACTERISATION AND EVALUATION OF ANTIBACTERIAL EFFECT OF SILVER NANOPARTICLES
(PSG College of Technology, Coimbatore, 2015-08-07) Sharmila C; Chandarshekar B; Ranjith R
Silver nanoparticles have attracted much attention in recent years. At low concentration these silver nanoparticles are non-toxic in nature and have a broad spectrum of antibacterial actions. Many methods are being investigated for the efficient production of silver nanoparticles among which green synthesis process using plant extract showed more successive rate. Employing plants towards the synthesis of nanoparticles are more advantageous because these plants can act as capping and reducing agent and hence increase the rate of reduction and stabilization of nanoparticles. In this present study silver nanoparticles were synthesized by silver nitrate solution dissolved in distilled water with guava leaves as reducing agent. The biosynthesized nanoparticles were characterized with different characterization techniques. The presence of silver nanoparticles was confirmed by UV-VIS, XRD, FTIR and SEM spectroscopic techniques. Antibacterial activity study was also carried out for the biosynthesized silver nanoparticles.
PHOTOCATALYTIC DEGRADATION OF POLYSTYRENE AND POLYSTYRENE-AG NANOCOMPOSITE
(Coimbatore Institute of Technology (CIT), Coimbatore, 2015-12-02) D, Anitha Jennifer; S, Sindhu; N, Priyadharsini
In this work, the solid-phase photocatalytic degradation of polystyrene (PS) and polystyrene-silver (Ag) nanocomposite were investigated under the ambient air in order to assess the feasibility of developing photodegradable polymers. PS-Ag nanocomposites were prepared by using PS solution in which various weight percentage (10, 20) of Ag nanoparticles were dispersed by constant stirring. The prepared nanocomposites such as PS, PS-10%Ag and PS-20%Ag were exposed to UV irradiation for various time intervals i.e. 30, 60, 90 and 120 h. On increasing irradiation time, increase in degradation efficiency was observed. Moreover, the effect of UV radiation on its structural, optical and degradation properties of various PS-Ag nanocomposite has been studied. Further, SEM analysis reveals the morphological nature of the nanocomposites and confirms the degradation of nanocomposites. Results shows that an increase in Ag concentration with Polystyrene enhances the photo-catalytic degradation of PS-Ag nanocomposite. Hence the influence of Nano silver particles and its efficient contribution in degradation of polymer was confirmed.
TIGHT FOCUSING OF AZIMUTHALLY POLARIZED AXISYMMETRIC BESSEL-MODULATED GAUSSIAN VORTEX
(Coimbatore Institute of Technology, Coimbatore jointly with Bergen University college , Norway, 2015-12-02) D, Niveditha
Focusing properties of the azimuthally polarized axisymmetric Bessel-modulated Gaussian beam optical vortex focused through a dielectric interface by in high numerical aperture system is investigated theoretically by vector diffraction theory. Results show that intensity distribution in focal region can be altered considerably by beam parameter μ and polarization angle. While μ alters axial intensity distribution remarkably, focal splitting may occur with tunable focal shift, and real value μ also may induce local intensity minimum. For certain case, with increasing imaginary value μ, transverse focal spot shrinks accompanied with higher full width half maximum of axial intensity distribution,which is suitable for application such as optical manipulation and optical trapping.
PERFORMANCE EVOLUTION OF AG-TIO2 NANO COMPOSITE BASED FIBER OPTIC SURFACE PLASMON RESONANCE SENSOR
(Post Graduate and Research Department of Chemistry and Physics held at PSGR Krishnammal College for Women, Coimbatore, 2015-12-07) M, Tharani; N, Priyadharsini
In this work, the solid-phase photocatalytic degradation of polystyrene (PS) and polystyrene-silver (Ag) nanocomposite were investigated under the ambient air in order to assess the feasibility of developing photodegradable polymers. PS-Ag nanocomposites were prepared by using PS solution in which various weight percentage (10, 20) of Ag nanoparticles were dispersed by constant stirring. The prepared nanocomposites such as PS, PS-10%Ag and PS-20%Ag were exposed to UV irradiation for various time intervals i.e. 30, 60, 90 and 120 h. On increasing irradiation time, increase in degradation efficiency was observed. Moreover, the effect of UV radiation on its structural, optical and degradation properties of various PS-Ag nanocomposite has been studied. Further, SEM analysis reveals the morphological nature of the nanocomposites and confirms the degradation of nanocomposites. Results shows that an increase in Ag concentration with Polystyrene enhances the photo-catalytic degradation of PS-Ag nanocomposite. Hence the influence of Nano silver particles and its efficient contribution in degradation of polymer was confirmed.
PLASMONIC STRUCTURES GENERATED BY RADIALLY POLARIZED SINH GAUSSIAN BEAM
(PSGR Krishnammal College for Women, 2015-12-07) S, Sowmya
The numerical investigation on plasmonic structures generated by excitation of surface plasmon using radially polarized Sinh gaussian beam based on vector diffraction theory is studied. It is observed that by suitably altering the beam waist ratio and beam order corresponding to various topological charges can generate a plasmonic structures with confined spot and larger focal depth. The side lobe intensity is found to vary drastically with increase in beam order and beam waist ratio for every topological charges considered. Thus by properly increasing the beam ratio value and beam order generates a highly confined focal spot with larger focal depth. Due to its higher resolution this beam finds application in optical trapping, high resolution imaging and optical data storage.
TIGHT FOCUSING OF AZIMUTHALLY POLARIZED COSH GAUSSIAN VORTEX BEAMS THROUGH DIELECTRIC INTERFACE
(PSGR Krishnammal College for Women, 2015-12-07) D, Niveditha
Focusing properties of the azimuthally polarized Cosh Gaussian beam optical vortex focused through a dielectric interface by in high numerical aperture system is investigated theoretically by vector diffraction theory. Results show that intensity distribution in focal region can be altered considerably by beam ratio β and beam order. Increase in beam order and beam ratio, the spot size is found to be reduced and improvement in the focal depth is observed. The side lobe intensity is found to increase with increase in beam order for every beam ratio considered. Thus by properly increasing the beam ratio value and beam order generates a highly confined focal spot with maximum side lobe intensity maximum depth of focus. This beam finds application in Optical trapping , high resolution imaging and Optical recording
IMPACT OF CO-AG DOPING ON STRUCTURAL, OPTICAL AND MORPHOLOGICAL PROPERTIES OF ZINC OXIDE NANOPARTICLES
(PSG College of Technology, Coimbatore, 2015-12-30) Balavijayalakshmi J; Meena K
Zinc oxide nanoparticles have attracted great attention in recent years because of its unique properties and versatile applications in transparent electronics, ultraviolet (UV) light emitters, piezoelectric devices, chemical sensors and spintronics. ZnO has high chemical stability and low toxicity, which is widely used as an active ingredient for dermatological applications in creams, lotions and ointments on an account of its antibacterial properties. Doped ZnO shows maximum effect against pathogenic organisms as compared to ZnO, there by using nanoparticles as an antimicrobial agent. In the present investigation, an attempt is made to synthesize Co-Ag co-doped Zinc oxide nanoparticles by chemical co-precipitation method. Zinc Chloride, Cobaltous chloride, Silver nitrate and sodium hydroxide is used as raw materials. The synthesized nanoparticles are subjected to X-ray diffraction technique to calculate the average nano-crystalline size using Debye – Scherrer formula and are found to be around 25 nm. The optical properties are characterized by UV-Vis spectral analysis. The FT-IR spectrum of the sample is recorded and the characteristic absorption bands are observed. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM). These co-doped (Co, Ag) ZnO nanoparticles may be used as antibacterial reagents to treat diseases caused by bacteria and fungi.
EFFECT OF MN DOPING ON STRUCTURAL, MAGNETIC AND MORPHOLOGICAL PROPERTIES OF MAGNESIUM-COBALT MIXED FERRITE NANOPARTICLES
(PSG College of Technology, Coimbatore, 2015-12-30) Balavijayalakshmi J; Annie Josphine C
Nano structured magnetic materials have wide areas of applications in water purification, high density data storage, ferrofluids, bio-molecule separation, colour imaging, medical diagnosis, drug delivery and so forth. Among the ferro spinels, Magnesium ferrite belongs to a class of compounds having the general formula MgFe2O4 crystallizing with the spinel structure. It is a typical spinel in which the cation distribution in the crystal lattice site is very much sensitive to heat treatment due to high diffusibility of Mg2+ ions. The physical and chemical properties of ferrites are dependent upon factors such as annealing temperature, annealing time, rate of heating and rate of cooling, etc. In case of cobalt ferrite, the incorporation of cobalt ions results in an increase in coercivity, which is due to the coupling of the spins of cobalt and iron ions. Also, manganese ferrite is considered versatile and of higher significance owing to its high saturation magnetization and low power loss at high frequencies. In the present work, an attempt is made to synthesize manganese doped magnesium-cobalt mixed ferrite nanoparticles (Mg0.4Co0.4Mn0.2Fe2O4) by co-precipitation method. Magnesium chloride, Cobaltous chloride, Manganese Chloride and sodium hydroxide are used as raw materials. The synthesized nanoparticles are annealed at 600○C and are subjected to X-ray diffraction technique to calculate the average nano-crystalline size using Debye – Scherrer formula. The FT-IR spectrum of the sample is recorded and the characteristic absorption bands are observed. The morphological analysis of the sample is studied using Scanning Electron Microscope (SEM). The magnetic measurements are made using Vibrating sample magnetometer (VSM). These materials can be tested for gas sensing applications.
GREEN SYNTHESIS OF IRON NANOPARTICLES USING BEET GREEN LEAVES AS NATURAL REDUCING AGENTS
(CIT, Coimbatore, 2016-02-29) Balavijayalakshmi J; Ponpoorani A
Magnetic nanoparticles have emerged as a new class of important nanoparticles as they possess many exceptional properties like superparamagnetism, high coercivity, and so forth. These nanoparticles, when synthesized by conventional methods, have several limitations. Chemical synthesis methods involve the usage of toxic chemicals, formation of hazardous byproducts, and contamination from precursor chemicals. Hence, there is a growing need to develop clean, nontoxic and environment-friendly procedures for nanoparticle synthesis. In this present study, the plant extract of beet green (BETA VULGARIUS) acts as the low cost reducing and stabilizing agents. Magnetic nanoparticle synthesis is carried out at room temperature by mixing plant extract with ferric chloride solution in a fixed ratio. The formation and characterization of iron nanoparticles are confirmed by UV-Vis spectroscopy, X-Ray diffraction (XRD), Fourier Transmission infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM). The XRD analysis confirmed that the iron nanoparticles (FeNPs) are crystalline in nature. The FT-IR analysis revealed that bio molecules are involved in the synthesis and capping of iron nanoparticles. The morphology of the FeNPs is studied using SEM analysis. The green synthesis of magnetic nanomaterials may be utilized in the adsorption and remediation of heavy metal ions in soil and waste water.