CRYSTALLIZATION ON A NUCLEUS OF A COMBINED STRUCTURE IN SUPERCOOLED LIQUID-SODIUM - COMPUTER EXPERIMENT

Crystallization of supercooled liquid sodium has been studied. A cryst alline fragment of the initial microheterogeneous system was construct ed as a combination of bcc and fee lattices. Crystallization of a syst em containing a 43-atom crystalline fragment resulted in the formation of a bcc structure with defects, whereas the presence of an 80-atom n ucleus gave rise to the formation of a polycrystal with two blocks cha racterized by the bcc and the fee packings, respectively. The block bo undaries seem to be formed by edge dislocations.