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Tamilnadu, India

Krishnan C.,Arignar Anna College | Pari S.,National College
Current Applied Physics | Year: 2010

Single crystals of undoped (pure) and sodium chloride (NaCl)-doped Zinc Tris-thiourea Sulphate (ZTS) were grown from aqueous solutions by slow evaporation technique. Morphological alterations have been observed when NaCl is doped into ZTS crystals. Density of the grown crystals was measured by floatation method. The values of unit cell parameters from single crystal X-ray diffraction (XRD) studies show that pure and sodium chloride-doped ZTS crystals are in orthorhombic structure. Impurity concentration in the doped crystals was estimated by using an atomic absorption spectrometer. Second Harmonic Generation (SHG) test for the undoped and NaCl-doped ZTS crystals was performed by the powder technique of Kurtz and Perry using a pulsed Nd:YAG laser. Microhardness studies show that hardness number (Hv) increases with load for all the grown crystals of this work. From the values of work hardening coefficients, it is concluded that pure and sodium chloride-doped ZTS crystals belong to the category of soft materials. UV-vis-NIR spectra show that the grown crystals have wide optical transparency in the entire visible region. Birefringence studies of the grown samples have been performed by channelled spectrum method. The thermal stability of the materials is found to be increasing with the doping concentration of sodium chloride (NaCl) in the lattice of ZTS crystals. © 2009 Elsevier B.V. All rights reserved. Source


Shanthi A.,Government of Tamilnadu | Krishnan C.,Arignar Anna College
Journal of Crystal Growth | Year: 2014

A novel organic nonlinear optical (NLO) material viz. N,N-dimethylurea picrate (NNDMP) was grown by the slow evaporation technique using N,N-dimethyl formamide as a solvent. The solubility of the grown sample has been estimated for various temperatures. The XRD study reveals that the grown crystal crystallizes in the monoclinic crystal system and the corresponding lattice parameters were determined. The relative second harmonic generation (SHG) efficiency of the NNDMP was found to be 1.045 times that of KDP by Kurtz-Perry powder technique. FTIR and FT-Raman spectral analyses explain the various functional groups present in the sample. The optical spectral analysis of the grown crystal has been performed by UV-vis-NIR spectroscopy and the band gap energy was found out. The thermogravimetric analysis and differential thermal analysis (TG/DTA) reveal that the NNDMP crystal is stable at up to 172 °C. A prominent first-order ferroelectric to paraelectric phase transition at 323 K has been observed and activation energy was determined for the AC conduction process in the sample. © 2013 Elsevier B.V. Source


Mohan Das N.,P.A. College | Sivakama Sundari S.,Arignar Anna College | Karuppusamy S.,The Madura College Autonomous | Mohan V.R.,Ethnopharmacology Unit | Parthipan B.,P.A. College
Asian Journal of Pharmaceutical and Clinical Research | Year: 2014

Objective: GC-MS (Gas chromatography and mass spectroscopy) analysis of ethanol extracts of leaf and stem bark of Cleidion nitidum was carried out to detect the bioactive components. Methods: The chemical compositions of the ethanolic extract of leaves and bark of Cleidion nitidum were investigated using Perkin - Elmer Gas Chromatography - Mass Spectra while mass spectra of the compounds found in the extract was matched with the National Institute of Standards of Technology (NIST) library. Results: Gas chromatography mass spectra (GC-MS) analysis revealed the presence of 16 compounds from leaves and 5 compounds from bark of the Cledion nitidum were identified. In GC-MS analysis, some of the phytocomponents screened were squalene, 3, 7, 11, 15-Tetramethyl-2, hexadecen-1-ol, Phytol and Vitamin E in leaves whereas, Thiophene-3-carbonitrite tetrahydro-4-oxo-, Dimethyl-2,6,10-dodecatrien-1-ol, D-Mannotetradecane-1,2,3,4,5-pentaol and Octanal 7-methoxy-3-7-dimethyl (5.13%) major compounds in the bark extract. Conclusion: These results indicate the ethanol extract of leaf and stem bark of Cleidion nitidum possesses potent anti-tumor, anticancer, cancer preventive, anti-inflammatory, antioxidant, antibacterial and pesticide effects so that it can be recommended as a plant of phytopharmaceutical importance. Source


Shanthi A.,Rani Anna College | Krishnan C.,Arignar Anna College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

An organic single crystal of Urea Adipic acid (UAA) was successfully grown in methanol solvent by slow solvent evaporation technique at room temperature (30 C). The structure of grown crystal was elucidated from the X-ray diffraction study and it belongs to monoclinic system with centrosymmetric space group P21/c. The optical transmission spectrum of UAA has been recorded and its theoretical calculations were carried out to determine the linear optical constants such as linear absorption coefficient, extinction coefficient, refractive index and reflectance etc. The third-order nonlinearities of UAA crystal have been investigated by Z-scan method. The values of nonlinear refractive index (n2), the absorption coefficient (β) and third-order nonlinear susceptibility (χ(3)) are found to be the order of 0.96 × 10-10 cm2/W, 1.248 × 10 -4 cm/W and 6.44 × 10-8 esu respectively. Fourier Transform Infra Red and Raman spectroscopy studies reveal the intermolecular interactions present in the UAA sample. The dielectric and mechanical measurements of the title compound are also reported. © 2013 Elsevier B.V. All rights reserved. Source


Sajikumar A.C.,Malankara Catholic College | Vinu S.,Kamarajar Government Arts College Surandai | Vinu S.,Indian National Institute for Interdisciplinary Science and Technology | Krishnan C.,Arignar Anna College
Journal of Thermal Analysis and Calorimetry | Year: 2015

Potassium hydrogen phthalate single crystals were grown by slow evaporation technique with strontium metal as dopant. The grown crystals were subjected to powder XRD analysis, and the result shows that the Sr2+ ions do not alter the crystal structure, but it enters into the crystal lattice. The optical transparency of the grown crystals was studied by UV-visible spectroscopy. The FTIR analysis was performed to confirm the group ligands in the sample. TG/DTA studies reveal the purity and thermal stability of the sample. In addition to this, the electrical parameters such as dielectric constant, dielectric loss and activation energy are studied. © 2014 Akadémiai Kiadó, Budapest, Hungary. Source

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