• T N Sairam

      Articles written in Bulletin of Materials Science

    • 57Fe Mössbauer and positron lifetime studies of Al-Cu-Fe quasicrystals

      C M Chittaranjan T N Sairam K P Gopinathan C S Sundar

      More Details Abstract Fulltext PDF

      Al61·4Cu22·7Fe15·9, Al63·2Cu21·8Fe15 and Al71Cu14Fe15 have been studied by Mössbauer, positron annihilation and X-ray diffraction techniques. The positron lifetime, measured as a function of temperature, in Al61·4Cu22·7Fe15·9 shows a two-step increase. This is found to be due to the dynamics of phasons associated with Al and Cu, having activation energies of 0·43 eV and 0·78 eV respectively. In the case of Al71Cu14Fe15, a phase transformation from the quasicrystalline-crystalline phase at ≈ 550°C is observed.

    • Mössbauer and XRD studies on the effect of doping iron in KCaY(PO4)2

      T N Sairam G V Narasimha Rao B Viswanathan

      More Details Abstract Fulltext PDF

      The effect of doping iron at the yttrium site in hexagonal KCaY(PO4)2 is studied for various concentrations ofx (0≤x≤1), of iron using Mössbauer and X-ray diffraction methods. For low iron concentrations, very little changes in structure are seen but atx≈0·1, onset of new peaks in the XRD pattern is observed. The Mössbauer study of the doped samples reveals that iron has a solubility of up to 2·5% in the parent phase with any excess iron precipitating out to form a new and unknown phase. From a detailed analysis of the X-ray diffraction pattern (corresponding tox=1) of the latter phase, it is found that this phase is rhombohedral with the possible space groupR3.

  • 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

© 2021-2022 Indian Academy of Sciences, Bengaluru.