Electron diffraction study on the rise of crystal phase in rare-gas and nitrogen clusters

Abstract

The structure of Ar N , Kr N , Xe N and (N 2) N clusters are studied by the electron diffraction method in a wide range of mean sizes N ̄ . It is found that rare-gas clusters of mean sizes N ̄ ⩾2000 atoms/cluster have a fcc structure with the “deformation”-type stacking faults. It is found that in the case of nitrogen clusters as N ̄ increases the cluster structure transforms in the sequence: quasi-crystal (icosahedron)→α (cubic) phase→β (hcp) phase. The formation of the cubic phase from the icosahedral structure follows the mechanism typical of rare gases. The transition α→β is due to the increase of the cluster temperature with size. The results obtained support the theoretical hypothesis on the important role of the kinetic factor in the formation of atomic cluster structures.