中国物理B ›› 2010, Vol. 19 ›› Issue (8): 80516-080516.doi: 10.1088/1674-1056/19/8/080516

• GENERAL • 上一篇    下一篇

Relaxation theory of spin-3/2 Ising system near phase transition temperatures

Osman Canko, Mustafa Keskin   

  1. Department of Physics, Erciyes University, 38039 Kayseri, Turkey
  • 收稿日期:2009-09-28 修回日期:2009-11-07 出版日期:2010-08-15 发布日期:2010-08-15
  • 基金资助:
    Project supported by the Erciyes University Research Funds (Grand No. FBT-03-09).

Relaxation theory of spin-3/2 Ising system near phase transition temperatures

Osman Canko and Mustafa Keskin   

  1. Department of Physics, Erciyes University, 38039 Kayseri, Turkey
  • Received:2009-09-28 Revised:2009-11-07 Online:2010-08-15 Published:2010-08-15
  • Supported by:
    Project supported by the Erciyes University Research Funds (Grand No. FBT-03-09).

摘要: Dynamics of a spin-3/2 Ising system Hamiltonian with bilinear and biquadratic nearest-neighbour exchange interactions is studied by a simple method in which the statistical equilibrium theory is combined with the Onsager's theory of irreversible thermodynamics. First, the equilibrium behaviour of the model in the molecular-field approximation is given briefly in order to obtain the phase transition temperatures, i.e. the first- and second-order and the tricritical points. Then, the Onsager theory is applied to the model and the kinetic or rate equations are obtained. By solving these equations three relaxation times are calculated and their behaviours are examined for temperatures near the phase transition points. Moreover, the z dynamic critical exponent is calculated and compared with the z values obtained for different systems experimentally and theoretically, and they are found to be in good agrement.

Abstract: Dynamics of a spin-3/2 Ising system Hamiltonian with bilinear and biquadratic nearest-neighbour exchange interactions is studied by a simple method in which the statistical equilibrium theory is combined with the Onsager's theory of irreversible thermodynamics. First, the equilibrium behaviour of the model in the molecular-field approximation is given briefly in order to obtain the phase transition temperatures, i.e. the first- and second-order and the tricritical points. Then, the Onsager theory is applied to the model and the kinetic or rate equations are obtained. By solving these equations three relaxation times are calculated and their behaviours are examined for temperatures near the phase transition points. Moreover, the z dynamic critical exponent is calculated and compared with the z values obtained for different systems experimentally and theoretically, and they are found to be in good agrement.

Key words: spin-3/2 Ising system, Onsager theory

中图分类号:  (Classical spin models)

  • 75.10.Hk
75.10.Dg (Crystal-field theory and spin Hamiltonians) 75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)) 75.40.Cx (Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)) 75.40.Gb (Dynamic properties?)