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

作　　者：Aamir Shahzad Maogang He Sheeba Ghani Muhammad Kashif Tariq Munir Fang Yang 

机构地区：[1]Molecular Modeling and Simulation Laboratory, Department of Physics, Government College University Faisalabad (GCUF) [2]Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, Xi’an Jiaotong University [3]Department of Physics, University of Engineering and Technology (UET) Lahore [4]College of Physics, Civil Aviation University of China

出　　处：《Chinese Physics B》2019年第5期181-188,共8页中国物理B（英文版）

基　　金：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(3 D) nonideal complex systems(NICSs) have been measured over a wide range of plasma states(■, κ) for a body-centered cubic(BCC) structure. The projected technique provides accurate ODstructures with fast convergence and applicable to very small size effect for different temperatures(≡ 1/■) 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 3 D simulation results.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(3 D) nonideal complex systems(NICSs) have been measured over a wide range of plasma states(■, κ) for a body-centered cubic(BCC) structure. The projected technique provides accurate ODstructures with fast convergence and applicable to very small size effect for different temperatures(≡ 1/■) 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 3 D simulation results.

关 键 词：NONEQUILIBRIUM molecular dynamics CRYSTALLINE structures nonideal complex systems DUSTY PLASMAS STRONGLY coupled REGIME 

分 类 号：O4[理学—物理]