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

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 the ^ z 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 structural phase transition from hexagonal (often also referred as triangular ) to square lattice configurations. A reentrant phase transition from hexagonal to square (and rhombic) structure has been observed in the simulations.