• Annamma John

      Articles written in Bulletin of Materials Science

    • Influence of lead oxide addition on LnTiTaO6 (Ln = Ce, Pr and Nd) microwave ceramics

      H Padma Kumar J K Thomas Annamma John Sam Solomon

      More Details Abstract Fulltext PDF

      The effect of PbO addition on the structural, processing and microwave dielectric properties of LnTiTaO6 (Ln = Ce, Pr and Nd) ceramics are reported. Conventional solid state ceramic route was used for the preparation of samples. Phase pure LnTiTaO6 (Ln = Ce, Pr and Nd) ceramics are prepared at a calcination temperature of 1300°C. The samples are sintered at optimized temperatures. Addition of PbO reduces the sintering temperature. The crystal structure of the materials was analysed using X-ray diffraction techniques and the surface morphology of the sintered samples was analysed using scanning electron microscopy. The dielectric constant at microwave frequency range decreases for higher PbO addition for all the samples but the quality factor improves on small PbO addition. The thermal stability of resonant frequency was also improved with PbO addition on all the systems. A number of samples with improved microwave dielectric properties were obtained on all the systems suitable for practical applications.

    • Synthesis of CeO$_2$ nanostructures with its exceptional biological and chemocatalytic activities: a comparative study


      More Details Abstract Fulltext PDF

      A comparative study has been carried out on the synthesis of nanostructured CeO$_2$ through chemical and biological methods. CeO$_2$ nanoparticles have been synthesized chemically using oxalic acid. The as-synthesizednanoparticles have been stabilized using the capping agent, polyvinylpyrrolidone. The aqueous leaf extract of Annona reticulata has been utilized for the biofabrication of CeO$_2$ nanoparticles. XRD, TEM and Raman analyses have been carried out to determine the structure and formation of the as-synthesized products. Optical studies have been carried out through UV–visible absorption, photoluminescence, Fourier transform infrared and Raman spectroscopic techniques. The biosynthesized CeO$_2$ nanoparticles exhibit strong antioxidant activity as well as potent antidiabetic and wound healing activities in comparison to their chemically fabricated counterparts, extending the possibility for their application in pharmaceuticals. The biogenic nanoparticles also exhibit superior catalytic activity in the degradation of harmful dyes including methylene blue and eosin yellowish.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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