• D Tirupathi Swamy

      Articles written in Bulletin of Materials Science

    • Evidence for high ionic conductivity in lithium–lanthanum titanate, Li0.29La0.57TiO3

      D Tirupathi Swamy K Ephraim Babu V Veeraiah

      More Details Abstract Fulltext PDF

      Lithium–lanthanum titanate, Li0.29La0.57TiO3, is prepared by solid-state reaction method and it is furnace-cooled to room temperature. X-ray diffraction results indicated that the compound has tetragonal perovskite-like structure and the lattice parameters are determined as 𝑎 = 3.8714 Å and 𝑐 = 7.7370 Å. The average grain size is found to be 5 𝜇m from SEM micrograph. The analysis of FTIR and Raman spectra of the sample supported tetragonal structure inferred from XRD data. The impedance spectrum of the sample is separated into bulk and grain boundary parts by analysing the impedance data. The high bulk ionic conductivity is reported as 1.12 × 10-3 S cm-1 at room temperature. D.C. conductivity measurements indicate that the compound is a good ionic conductor.

    • Structural and optoelectronic properties of cubic perovskite RbPbF3

      K Ephraim Babu N Murali D Tirupathi Swamy V Veeraiah

      More Details Abstract Fulltext PDF

      The structural and optoelectronic properties of cubic perovskite RbPbF 3 are calculated using all electrons full potential linearized augmented plane wave (FP-LAPW) method. The calculated lattice constant is in good agreement with the experimental result. The calculated band structure shows a direct band gap of 3.07 eV. The contribution of different bands is analysed from the total and partial density of state curves. We identified hybridization of Pb 𝑠, Pb 𝑝 states with F 𝑝 states in the valence bonding region. Calculations of the optical spectra, viz., the dielectric function, optical reflectivity, absorption coefficient, real part of optical conductivity, refractive index, extinction coefficient and electron energy loss are performed for the energy range of 0-30 eV. Based on the direct bandgap, as well as other optical properties of the compound, it is predicted that this material is useful for vacuum-ultraviolet-transparent (VUV-transparent) applications.

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    • 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
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