Modeling Superionic Behavior of Plutonium Dioxide


GÜNAY S. D. , AKGENC B., TAŞSEVEN Ç.

HIGH TEMPERATURE MATERIALS AND PROCESSES, cilt.35, sa.10, ss.999-1004, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 35 Konu: 10
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1515/htmp-2015-0133
  • Dergi Adı: HIGH TEMPERATURE MATERIALS AND PROCESSES
  • Sayfa Sayıları: ss.999-1004

Özet

The Bredig transition to the superionic phase indicated with the.-peak in C-p was highly expected for plutonium dioxide (PuO2) as other actinide dioxides. However, least-square fit and local smoothing techniques applied to the experimental enthalpy data of PuO2 in 1980s could not detect a.-peak in specific heat that might be due to too scattered and insufficient experimental data. Therefore, this issue has not been yet put beyond the doubts. In the current article, a superionic model of PuO2 is developed with partially ionic model of a rigid ion potential. Thermophysical properties were calculated in constant pressure-temperature ensemble using molecular dynamics simulation. The Bredig transition with vicinity of a lambda-peak in specific heat was successfully observed for the model system at about 2,100 K. Moreover, the experimental enthalpy change was well reproduced before and after the estimated transition temperature.