Molecular Dynamics Study of the Phase Diagram of Silver Iodide

  • C. A. Rains
  • J. R. Ray
  • P. Vashishta
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 72)


Molecular dynamics studies have been carried out to investigate structural phase transformations in AgI as the temperature is lowered below the superionic transition temperature of ≈ 420 K while holding the pressure constant at selected values. Upon lowering the temperature for pressures below 0.27 GPa the system always transformed from the superionic phase, α-AgI, into the wurtzite phase, β-AgI. Starting from the superionic phase and lowering the temperature at the pressures of 0.28, 0.29, 0.30, and 0.31 GPa, we obtained various polytypes of the same hexagonality as has been reported experimentally. At pressures above 0.32 GPa the structure obtained upon temperature lowering was always the rocksalt form of AgI in agreement with previous simulations and experiments. At pressures between 0.31 and 0.32 GPa the system did not transform but underwent sluggish distortions among unrecognizable structures over the entire time of the simulation. This “frustration” of the system near the polytype/rocksalt phase boundary may be associated with the, so called, intermediate phase mentioned in the literature.


Pair Distribution Function Silver Iodide Rocksalt Structure Structural Phase Transformation Experimental Phase Diagram 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • C. A. Rains
    • 1
  • J. R. Ray
    • 1
  • P. Vashishta
    • 2
  1. 1.Department of Physics and AstronomyClemson UniversityClemsonUSA
  2. 2.Concurrent Computing Laboratory for Material Simulations, Dept. of Physics and Astronomy and Dept. of Computer ScienceLouisiana State UniversityBaton RougeUSA

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