Electron diffraction studies of supersonic jets. VII. Liquid and plastic crystalline carbon tetrachloride

Carbon tetrachloride at 3–11 mol % in neon carrier produces clusters of CCl4 molecules in flow through a Laval nozzle. Electron diffraction patterns of the clusters formed at a total pressure below 2.5 bar are intermediate between x-ray diffraction patterns of bulk liquid CCl4 and neutron patterns of the amorphous material formed by condensation at 10 K. Strong, sharp interference features at low angle imply appreciable long range order, perhaps beyond 50 Å, in the clusters, whose temperatures are about 210 K. When carrier partial pressure is increased beyond 2.6 bar, clusters begin to exhibit crystallinity. Crystallites belong to the rhombohedral plastic-crystalline phase Ib, a=14.27 Å and α=90.0°.