Crystallization waves in complex plasmas: numerical simulations

Molecular dynamics (MD) simulation of crystallization wave formation and evolution in Yukawa systems is presented. We have found the coexistence of various lattice types (including metastable ones) behring crystallization wave front. Local order analysis shows the presence of fcc, bcc and hcp phases - it is a clear manifestation of nonequilibrium phase transition in the system. Kinetic observations of crystal growth in real time are possible by using complex plasmas. A plasma crystal is first melted into a disordered liquid-like phase (e. g., by a short increase of the plasma discharge power). Afterwards, the system starts to recrystallized. Often this occurs in the form of a crystallization wave (CW) propagating in the direction of the decreasing particle density, against gravity. We provide MD simulations of the crystallization process, revealing the qualitative features observed in experiments. After the CW front passed, the crystalline structures formed behind the front revealing a sequence of transitions from one lattice configuration to another. (Author)