• S K SARKAR

      Articles written in Bulletin of Materials Science

    • Synthesis of sequentially-deposited Cu/BaF2/Y films on SrTiO3 and buffered Si substrates

      P K Ashwini Kumar M L Sharma Avijit Chowdhary S K Sarkar

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      Sequentially-deposited layers of Cu/BaF2/Y on buffered Si and SrTiO3 substrates have been synthesised to produce YBa2Cu3O7−δ thin film. An attempt has been made to see the effect of the ZrO2 and Al buffer layers on Si of the annealing of the layered structure. X-ray diffraction studies reveal that on ZrO2-buffered Si the annealing of the layered structure leads to formation of 211 phase while on Al-buffer layer 123 phase is obtained. Noticeable effect in annealed-layered structure of oblique deposition of BaF2 from a Knudson Cell is seen in X-ray diffraction.

    • Magnetodielectric effects in three reduced graphene oxide–polymer nanocomposites

      S S PRADHAN T N GHOSH A MARIK K K RAUL S K SARKAR

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      Three polymers, poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(methyl methacrylate) (PMMA), are used as matrices to synthesize three nanocomposites each with reduced graphene oxide (RGO) fillers (5 wt%). The dielectric properties of these nanocomposites, RGO–PVA, RGO–PAA and RGO–PMMA, are studied in zero magnetic field and in magnetic field ($H$) up to 1.2 T. From these data magnetodielectric effects are obtained as the variation of $\epsilon^{\prime}$ and $\epsilon^{\prime\prime}$—the real and imaginary parts of complex dielectric constant with $H$ at some frequencies. Thus at 100 kHz for the increase of $H$ from zero to 1 T $\epsilon^{\prime}$ decreases by 5% in RGO–PVA and by 4% in RGO–PAA, whereas $\epsilon^{\prime}$ increases by 4% in RGO–PMMA. The observed magnetodielectric effects, though small, are significant. They show both decrease and increase of $\epsilon^{\prime}$ depending on the polymer. This fact is the indicative of the interaction between RGO filler particles and polymer chains.

  • 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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