中国物理B ›› 2019, Vol. 28 ›› Issue (5): 55201-055201.doi: 10.1088/1674-1056/28/5/055201

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

Crystalline order and disorder in dusty plasmas investigated by nonequilibrium molecular dynamics simulations

Aamir Shahzad, Maogang He, Sheeba Ghani, Muhammad Kashif, Tariq Munir, Fang Yang   

  1. 1 Molecular Modeling and Simulation Laboratory, Department of Physics, Government College University Faisalabad(GCUF), Allama Iqbal Road, Faisalabad 38040, Pakistan;
    2 Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China;
    3 Department of Physics, University of Engineering and Technology(UET) Lahore, Pakistan;
    4 College of Physics, Civil Aviation University of China, Tianjin 300300, China
  • 收稿日期:2018-10-04 修回日期:2019-02-17 出版日期:2019-05-05 发布日期:2019-05-05
  • 通讯作者: Aamir Shahzad E-mail:aamir.awan@gcu.ed.pk
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11505286 and 11805272).

Crystalline order and disorder in dusty plasmas investigated by nonequilibrium molecular dynamics simulations

Aamir Shahzad1,2,3, Maogang He2, Sheeba Ghani3, Muhammad Kashif1, Tariq Munir1, Fang Yang4   

  1. 1 Molecular Modeling and Simulation Laboratory, Department of Physics, Government College University Faisalabad(GCUF), Allama Iqbal Road, Faisalabad 38040, Pakistan;
    2 Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China;
    3 Department of Physics, University of Engineering and Technology(UET) Lahore, Pakistan;
    4 College of Physics, Civil Aviation University of China, Tianjin 300300, China
  • Received:2018-10-04 Revised:2019-02-17 Online:2019-05-05 Published:2019-05-05
  • Contact: Aamir Shahzad E-mail:aamir.awan@gcu.ed.pk
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11505286 and 11805272).

摘要: The particle structure of a complex system has been explored through a unique Evans's homogenous nonequilibrium molecular dynamics (HNEMD) simulation technique. The crystalline order-disorder structures (OD-structures) and the corresponding energies of three-dimensional (3D) nonideal complex systems (NICSs) have been measured over a wide range of plasma states (Γ, κ) for a body-centered cubic (BCC) structure. The projected technique provides accurate OD-structures with fast convergence and applicable to very small size effect for different temperatures (≡1/Γ) and constant force field (F*) values. The OD-structure obtained through HNEMD approach is found to be reasonable agreement and more reliable than those earlier identified by simulation approaches and experimental data of NICSs. New simulations of OD-structures show that dusty plasma remains in crystalline (strongly coupled) state at lower temperature and constant F* values, for the whole simulation runs. Our investigations show that the crystalline structure is changed and the particle structure switches from intermediate to disorder (nonideal gaseous) state with an increase of the system's temperature. It has been shown that the long range order shifts toward lower temperature with increasing κ. The presented technique exhibits that the potential energy has a maximum value when the dusty plasma remains in crystalline states (low temperatures), which confirms earlier 3D simulation results.

关键词: nonequilibrium molecular dynamics, crystalline structures, nonideal complex systems, dusty plasmas, strongly coupled regime

Abstract: The particle structure of a complex system has been explored through a unique Evans's homogenous nonequilibrium molecular dynamics (HNEMD) simulation technique. The crystalline order-disorder structures (OD-structures) and the corresponding energies of three-dimensional (3D) nonideal complex systems (NICSs) have been measured over a wide range of plasma states (Γ, κ) for a body-centered cubic (BCC) structure. The projected technique provides accurate OD-structures with fast convergence and applicable to very small size effect for different temperatures (≡1/Γ) and constant force field (F*) values. The OD-structure obtained through HNEMD approach is found to be reasonable agreement and more reliable than those earlier identified by simulation approaches and experimental data of NICSs. New simulations of OD-structures show that dusty plasma remains in crystalline (strongly coupled) state at lower temperature and constant F* values, for the whole simulation runs. Our investigations show that the crystalline structure is changed and the particle structure switches from intermediate to disorder (nonideal gaseous) state with an increase of the system's temperature. It has been shown that the long range order shifts toward lower temperature with increasing κ. The presented technique exhibits that the potential energy has a maximum value when the dusty plasma remains in crystalline states (low temperatures), which confirms earlier 3D simulation results.

Key words: nonequilibrium molecular dynamics, crystalline structures, nonideal complex systems, dusty plasmas, strongly coupled regime

中图分类号:  (Strongly-coupled plasmas)

  • 52.27.Gr
52.27.Lw (Dusty or complex plasmas; plasma crystals) 52.65.Yy (Molecular dynamics methods) 52.27.Lw (Dusty or complex plasmas; plasma crystals)