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Alwarkurichi, India

Ariharan V.N.,Sri Paramakalyani College | Nagendra Prasad P.,Noorul Islam Center for Higher Education
Rasayan Journal of Chemistry | Year: 2014

Aegle marmelos is an important medicinal plant used to treat many common ailments in Indian traditional systems of medicine. The present study was undertaken to find out a scientific validation for the efficacy of Aegle marmelos leaves as a natural antibiotic. Aqueous extract of Aegle marmelos leaves of the three morphological traits were prepared and screened for their antibacterial activity against some human pathogenic bacteria. © 2014 RASĀYAN. All rights reserved. Source

Varadhaseshan R.,Sri Paramakalyani College | Meenakshi Sundar S.,Sri Paramakalyani College
Applied Surface Science | Year: 2012

Ni doped ZnO (Zn 1-xNi xO, in which 0.1 ≤ x ≤ 0.4) diluted magnetic semiconductor nanoparticles are prepared by microwave irradiated solvothermal process. The structural properties are studied using X-ray diffraction. It is evident from the XRD spectrum that the Ni doped ZnO nanocompounds exhibit single phase hexagonal wurtzite structure with strong c-axis orientation. To improve the crystalline quality the samples are annealed at 400 °C. The effects of annealing temperature and dopant concentration on the structural properties are also discussed. Unit cell expansion is clearly observed in Ni doped ZnO nanocrystals. The TEM images confirm that the particle size is 20 nm and the particles are well dispersed. The magnetic property of the nanocrystals was measured using vibrational sample magnetometer. According to the magnetization measurements ferromagnetic behavior was found in Zn 0.9Ni 0.1O combination. However, for the other higher dopant ratios paramagnetism is observed. © 2012 Elsevier B.V. Source

Vettumperumal R.,Sri Paramakalyani College | Kalyanaraman S.,Sri Paramakalyani College | Thangavel R.,Indian School of Mines
Journal of Molecular Structure | Year: 2014

Nanocrystals of Na-doped and Na, Mg codoped ZnO thin films were prepared by sol-gel spin coating method on glass substrate at different annealing temperatures. The deposited films were characterized by X-ray diffraction (XRD), Micro Raman, photoluminescence (PL) and UV-Visible measurements. The codoped films had hexagonal wurtzite structure and there were no peaks belonging to Na and Mg or its oxides observed from XRD. Surface morphology of the films was scrutinized by scanning electron microscope (SEM) and atomic force microscope (AFM) showing wrinkle structures that appeared on the film surface. Elemental compositions of the films were analysed using energy dispersive X-ray (EDX) spectra. The LO phonon modes were observed up to the fifth order and their enhancement was observed by the presence of Frohlich contribution. From μ-PL, the strong near band edge emission observed at 3.24 eV was blue shifted due to the band filling of free carriers. Fundamental absorption edge was observed at 370 nm and the optical band gap was decreased with respect to ZnO. Reduction of Urbach energy among codopants is small indicating less disorder. © 2013 Elsevier B.V. Source

Vijayalakshmi S.,Sri Paramakalyani College | Kalyanaraman S.,Sri Paramakalyani College
Optical Materials | Year: 2013

The synthesis and non-linear optical properties of nitro aniline derived Schiff bases of 9-anthraldehyde were carried out. The compounds were characterized using FT-IR, Raman and UV-Vis spectroscopies. The FT-IR and Raman spectral data revealed the confirmation of Schiff bases with the absorption band assignable to the stretching of CN band. The charge transfer (CT) interaction between the donor and acceptor molecules were confirmed through λmax of the UV-Vis spectra. The UV-Vis analysis indicated, bathochromic shift in the compounds, implying a non-zero first order molecular hyperpolarizability (β) which are translated into macroscopic non-linearity χ2. To investigate the solid state macroscopic non-zero non-linear optical response, χ2, (second harmonic generation) the Kurtz and Perry method was used. This happens to be the first report on the non-linear optical analysis of these compounds. © 2012 Elsevier B.V. All rights reserved. Source

Kalyanaraman S.,Sri Paramakalyani College | Vettumperumal R.,Sri Paramakalyani College | Thangavel R.,Indian School of Mines
Journal of the Korean Physical Society | Year: 2013

Undoped and lithium-doped zinc oxide (ZnO) thin films have been deposited on sapphire substrates (0001) using the sol-gel method. The effect of doping with various percentages of Li at a particular annealing temperature of 600 °C is studied. The samples are characterized using Xray diffraction (XRD), scanning electron microscopy (SEM), micro-photoluminescence (μ-PL) and Raman and polarized Raman (PR) spectroscopy. The X-ray diffraction and micro-Raman spectroscopy confirm the presence of lithium substitution for zinc. The wurtzite structure of the lattice is retained, and five multiple phonon Raman modes are observed. The values of the depolarization ratios are calculated from polarized Raman data. Photoluminescence shows a strong emission peak in the near UV at 3. 276 eV and negligible visible emission. The PL peak positions in the doped samples nearly coincide with each other, suggesting very similar recombination mechanisms in the nanocrystals. © 2013 The Korean Physical Society. Source

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