Accession Number : ADA133863

Title :   Structure and Phase Transitions in Bromine and Potassium-Mercury Intercalated Graphite,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Erbil,A ; Timp,G ; Kortan,A R ; Birgeneau,R J ; Dresselhaus,M S

PDF Url : ADA133863

Report Date : Apr 1983

Pagination or Media Count : 21

Abstract : High resolution x-ray scattering and electron microscopy results relevant to the in-plane structure of two prototype graphite intercalation compound (GIC) systems, Br2-GIC and KHgx-GIC, are presented. Particular emphasis is given to intercalation kinetics and to structural coherence. Of special interest is the measurement using high resolution x-ray scattering of an intrinsic in-plane intercalate domain size in Br2-GIC larger than 10,000. Evidence is presented for the formation of a two-dimensional incommensurate domain wall structure for the Br2 intercalant along the 7-fold direction above T sub C = 69.08 C for stage 4 C28Br2. Evidence is also presented in the same compound for two-dimensional anisotropic melting at T sub M = 100.25 C. Large dislocation-free regions (100 a x 500 a) are observed directly in the lattice fringe images of a stage 1 KHg-GIC sample.

Descriptors :   *Graphite, *Phase transformations, *Crystal structure, *Molecular structure, Bromine, Potassium, Mercury, Interfaces, Reaction kinetics, Anisotropy, Melting, Domain walls, Dislocations, Crystal lattices, Layers, Prototypes, Coherence, Two dimensional, X ray scattering, Electron microscopy, Single crystals

Subject Categories : Organic Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE