CRYSTAL PHASE-FORMATION AND GROWTH IN RARE-GAS CLUSTERS

The structure of clusters formed in supersonic jets of heavy rare gase s is studied by the methods of electron diffractometry. It is found th at a crystalline fee structure with ''deformation-type'' stacking faul ts (SF) is formed in aggregates consisting of N greater than or equal to 2.10(3) atoms/cluster. The SF density is a linear function of N-1/3 . The number of ''defective'' planes does not depend on the cluster si ze and is equal to four in all cases. Such a number of intersecting SF leads to the formation of nonvanishing atomic steps ensuring a rapid and subsequently defectless growth of the cluster on all densely packe d planes facing the cubooctahedron. The obtained results confirm exper imentally the important role of the kinetic factor in the formation of the atomic structure of a cluster. (C) 1997 American Institute of Phy sics.