Molecular dynamics study of crystal formation and structural phase transition in Yukawa system for dusty plasma medium

Abstract

The layered crystal formation in dusty plasma medium depicted by the Yukawa interaction amidst dust has been investigated using molecular dynamics simulations. The multilayer structures are shown to form in the presence of a combined gravitational and external electric field force (representing the sheath field in experiments) along theẑ direction. A detailed study of the dependence of the number of crystal layer formation, their width etc., on various system parameters (viz., the external field profile and the screening length of Yukawa interaction) have been analyzed. The structural properties of crystalline bilayers have been studied in detail identifying their structures with the help of pair correlation function and Voronoi diagrams. It has been shown that the crystalline layers undergo a structural phase transition from hexagonal (often also referred to as triangular) to square lattice configurations. A reentrant phase transition from hexagonal to square (and rhombic) structure has been observed in the simulations.

Parametric decay induced first-order phase transition in a two-dimensional dusty plasma crystal

“…Here, ε 0 represents the electric permittivity in free space. In addition to the Yukawa pair interaction, particles are also subjected to the force due to gravity, m d g ( −z) acting vertically downward, and the force associated with an externally applied electric field QE ext = A exp −αz (ẑ) acting vertically upward for the negatively charged particles 15 . These two forces provide a vertical confinement potential with a parabolic form, as shown in Fig.…”

“…1. We have chosen the parameters A and α so that particles organize themselves in a 2D monolayer in the x − y plane levitating at a height z = L z /2 15 . The boundary conditions in x and ŷ directions are taken to be periodic.…”

“…These micron-sized charged particles can form a two-dimensional (2D) and three-dimensional (3D) ordered structure (also known as plasma crystal) under certain conditions, which are easily achievable in experiments. There are several experimental as well as theoretical studies on the formation of dusty plasma crystal 12,13,14,15 , static and dynamical phase behaviour of crystalline structure 16,17,18 , crystal cracking induced by energetic particles 19 , cluster formation 20,21,22 , and various dust lattice modes 23,24,25 .…”

Chaotic dynamics of small sized charged Yukawa Dust Clusters

“…The experiments involving such configurations of dust particles are easy to perform, and the trajectory of individual dust particles can also be tracked with sufficient detail and with very simple diagnostics. Such a system offers an ideal test-bed for studying crystallization process [9][10][11], single-particle dynamics [13][14][15], phase transitions [16][17][18], etc. The system thus provides a very convenient example for studying the dynamical behavior of a small cluster of interacting particles placed in any externally applied field.…”

Dynamical states in two-dimensional charged dust particle clusters in plasma medium

“…Thus, their dynamics can be easily visualized and captured even by normal charged-coupled devices. These unique properties make the dusty plasma medium to become an ideal model system for studying macroscopic correlated phenomena originating from the microscopic dynamics of particles, e.g., crystallization [22][23][24], phase transitions [25][26][27][28][29], transport processes [30][31][32][33][34], visco-elastic effects [15,[35][36][37], etc,.…”