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      https://www.ias.ac.in/article/fulltext/pram/063/02/0405-0408

    • Keywords

       

      Inelastic neutron scattering; phonons; thermal expansion

    • Abstract

       

      We report here measurements of phonon spectrum and lattice dynamical calculations for GaPO4. The measurements in low-cristobalite phase of GaPO4 are carried out using high-resolution medium-energy chopper spectrometer at ANL, USA in the energy transfer range 0–160 meV. Semiempirical interatomic potential in GaPO4, previously determined using ab-initio calculations have been widely used in studying the phase transitions among various polymorphs. The calculated phonon spectrum using the available potential show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarisability of the oxygen atoms in the framework of the shell model. The lattice dynamical models are also exploited for calculations of various thermodynamic properties of GaPO4.

    • Author Affiliations

       

      R Mittal1 S L Chaplot1 A I Kolesnikov1 2 C -K Loong1 2 O D Jayakumar1 3 S K Kulshreshtha1 3

      1. Solid State Physics Division, India
      2. Intense Pulsed Neutron Source Division, Argonne National Laboratory, Illinois - 60439, USA
      3. Novel Materials and Structural Chemistry Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India
    • Dates

       
  • Pramana – Journal of Physics | News

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