Effects of charge and mass variations on the structure in 2D one-component and two-component dusty plasmas

Using molecular dynamics simulation, we calculate the mean square displacement, the pair correlation function, the velocity autocorrelation function and the spectrum function of a two-dimensional (2D) charged dust system. Results show that the critical coupling constant Γ* for the phase transition from a liquid-like state to a solid-like state decreases with increasing charge and mass of particles in the one-component system. A scaling relation between Γ* and μ (Γ* ∼ μ-1.72±0.07) is given, where μ represents the quantities of charge and mass. In the system with two species of particles, the coagulation process is found to be delayed by the presence of one species, and Γ* is closer to that of the 'smaller' particles species, which has the smaller charge and mass