• Coherent potential approximation for a disordered diatomic linear chain having diagonal and off-diagonal randomness

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      https://www.ias.ac.in/article/fulltext/pram/019/05/0467-0482

    • Keywords

       

      Mixed crystals; impurity modes; lattice dynamics; coherent potential approximation; averaget-matrix approximation; diatomic linear chain

    • Abstract

       

      A coherent potential approximation (cpa) for a mixed diatomic linear chain including both mass and force constant changes has been developed. In this case an impurity atom substituted at a particular site in one of the sublattices couples with two nearest neighbour atoms in the other sublattices. The diatomic linear chain is therefore considered as a tetratomic linear chain, the size of the unit cell being twice the original. Thecpa density of states and the dielectric susceptibility have been calculated. The numerical values of the later have been calculated in theata (averaget-matrix approximation) limit. Comparison of these results with the experimental and other computer calculations show a qualitative agreement.

    • Author Affiliations

       

      P Nayak1 S N Behera1 2

      1. Department of Physics, G. M. College, Sambalpur - 768 004, India
      2. Institute of Physics, Bhubaneswar - 751 005, India
    • Dates

       
  • Pramana – Journal of Physics | News

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