CRYSTAL NUCLEATION AND GROWTH IN LIQUID RUBIDIUM

Molecular dynamics technique is used to study the homogeneous nucleation of an ordered stable phase from a liquidlike state of aggregation. The rubidium potential is used for a 500 particles system with reduced density 0.95. At the start of the calculation the system is quenched rapidly from a reduced temperature of 0.8 to 0.1. The moment of nucleation and the explosive growth of the nucleus to engulf the whole system have been monitored by studying the characteristics of Voronoi polyhedra in addition to quantities such as temperature, pressure, pair correlation functions, etc. After nucleation, the surface of the nucleus is found to advance at a rate of about 130 m/sec; the size of the critical nucleus is estimated to contain 40 to 70 particles. The ordered stable phase is found to have a bcc structure. In spite of the very rapid rate of cooling which was used to start the calculation, a metastable disordered structure was not obtained. © 1979 American Institute of Physics.