Orientational ordering transition in solid C sub 60

Journal Article · Mon Jun 03 04:00:00 EDT 1991 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.66.2911· OSTI ID:5558754

Heiney, P A; Fischer, J E; McGhie, A R; Romanow, W J; Denenstein, A M; McCauley, Jr, J P; Smith, A B ^[1]; Cox, D E ^[2]

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1. Laboratory for Research on Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (USA)
2. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (USA)

Synchrotron-x-ray powder-diffraction and differential-scanning-calorimetry measurements on solid C{sub 60} reveal a first-order phase transition from a low-temperature simple-cubic structure with a four-molecule basis to a face-centered-cubic structure at 249 K. The free-energy change at the transition is approximately 6.7 J/g. Model fits to the diffraction intensities are consistent with complete orientational disorder at room temperature, and with the development of orientational order rather than molecular displacements or distortions at low temperature.

• DOE Contract Number: FG02-86ER45254; AC02-76CH00016
• OSTI ID: 5558754
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 66:22; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
BREMSSTRAHLUNG
CARBON
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CUBIC LATTICES
DATA
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
EXPERIMENTAL DATA
FCC LATTICES
FREE ENERGY
INFORMATION
LOW TEMPERATURE
MEDIUM TEMPERATURE
NONMETALS
NUMERICAL DATA
ORDER PARAMETERS
ORDER-DISORDER TRANSFORMATIONS
ORIENTATION
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RADIATIONS
RANDOMNESS
SCATTERING
SOLIDS
SYNCHROTRON RADIATION
THERMODYNAMIC PROPERTIES
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
X-RAY DIFFRACTION