• A M Umarji

      Articles written in Bulletin of Materials Science

    • Thermal expansion studies on ferroelectric materials

      M V Radhika Rao A M Umarji

      More Details Abstract Fulltext PDF

      Thermal expansion data is reported over a wide temperature range (80–800 K) for BaTiO3 (BT) and Pb(Fe1/2 Nb1/2)O3 (PFN), belonging to different classes of the ferroelectric materials. The sharp structural phase transitions of BT result in lowering of the thermal expansion coefficient (α) at the transitions which is proportional to the change in polarization at the transitions. In PFN, a relaxor ferroelectric, lowering of α is spread over a wider temperature range across the dielectric maxima.

    • Microwave-assisted synthesis of reduced graphene oxide/V$_2$O$_5$ nano-composite as an efficient photocatalyst for dye degradation


      More Details Abstract Fulltext PDF

      In the present study, rapid and green microwave synthesis has been used to synthesize V$_2$O$_5$ and reduced graphene oxide decorated with V$_2$O$_5$, a hybrid nanocomposite (rGO/V$_2$O$_5$), using an inorganic precursor. The synthesized nanocomposite is characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and UV–visible spectroscopy. The photocatalytic activity of V$_2$O$_5$and rGO/V$_2$O$_5$ was studied by degrading methylene blue dye in sunlight. The kinetics of the dye degradation is studied by calculating the rate constant and the half-life of the degradation process. The rGO/V$_2$O$_5$ nanocomposite showed low resistance, thus increasing the diffusion of electrons, which prevents electron–hole recombination and hence enhances photocatalytic activity (80% degradation efficiency) when compared with bare V$_2$O$_5$.

  • 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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