中国物理B ›› 2008, Vol. 17 ›› Issue (8): 2867-2873.doi: 10.1088/1674-1056/17/8/019

• GENERAL • 上一篇    下一篇

Analytic equation of state for solids with multi-exponential potential based on analytic mean field potential approach and applied to the epsilon phase of solid oxygen

王立国, 孙久勋, 杨 维   

  1. Department of Applied Physics, University of Electronic Science and Technology, Chengdu 610054, China
  • 收稿日期:2007-09-05 修回日期:2008-04-03 出版日期:2008-08-20 发布日期:2008-08-20
  • 基金资助:
    Project supported by the Joint Foundation of National Natural Science Foundation of China and China Academy of Engineering Physics (Grant No 10476007), by the Program for New Century Excellent Talents in University (Grant No NCET-05-0799), and the Program for Excellent Talents of University of Electronic Science and Technology (Grant No 23601008).

Analytic equation of state for solids with multi-exponential potential based on analytic mean field potential approach and applied to the epsilon phase of solid oxygen

Wang Li-Guo(王立国), Sun Jiu-Xun(孙久勋), and Yang Wei(杨维)   

  1. Department of Applied Physics, University of Electronic Science and Technology, Chengdu 610054, China
  • Received:2007-09-05 Revised:2008-04-03 Online:2008-08-20 Published:2008-08-20
  • Supported by:
    Project supported by the Joint Foundation of National Natural Science Foundation of China and China Academy of Engineering Physics (Grant No 10476007), by the Program for New Century Excellent Talents in University (Grant No NCET-05-0799), and the Program for Excellent Talents of University of Electronic Science and Technology (Grant No 23601008).

摘要: The thermodynamic properties of the $\varepsilon $ phase of solid oxygen are studied by using the analytic mean field approach (AMFP). Analytic expressions for the Helmholtz free energy, internal energy and equation of state of solid oxygen have been derived based on the multi-exponential potential. The formulism for the case of double-exponential (DE) model is applied to the $\varepsilon $ phase of solid oxygen. Its four potential parameters are determined through fitting the experimental compression data of the $\varepsilon $ phase of solid oxygen. Numerical results of the pressure dependence of the volume calculated by using the AMFP are in good agreement with the original experimental data. This suggests that the AMFP is a useful approach to study the thermodynamic properties of the $\varepsilon $ phase of solid oxygen. Furthermore, we predict the variation of the volume, lattice parameters and intermolecular distances with pressure, and some thermodynamic quantities versus volume, at several higher temperatures.

Abstract: The thermodynamic properties of the $\varepsilon $ phase of solid oxygen are studied by using the analytic mean field approach (AMFP). Analytic expressions for the Helmholtz free energy, internal energy and equation of state of solid oxygen have been derived based on the multi-exponential potential. The formulism for the case of double-exponential (DE) model is applied to the $\varepsilon $ phase of solid oxygen. Its four potential parameters are determined through fitting the experimental compression data of the $\varepsilon $ phase of solid oxygen. Numerical results of the pressure dependence of the volume calculated by using the AMFP are in good agreement with the original experimental data. This suggests that the AMFP is a useful approach to study the thermodynamic properties of the $\varepsilon $ phase of solid oxygen. Furthermore, we predict the variation of the volume, lattice parameters and intermolecular distances with pressure, and some thermodynamic quantities versus volume, at several higher temperatures.

Key words: analytic equation of state, analytic mean field approach, solid oxygen, $\varepsilon $ phase

中图分类号:  (Equations of state of specific substances)

  • 64.30.-t
65.40.G- (Other thermodynamical quantities)