Specific Heat and Thermal Conductivity of Solid Fullerenes

• Published in: Science (American Association for the Advancement of Science) Vol. 259; no. 5098; pp. 1145 - 1148
• Main Authors: Olson, J. R., Topp, K. A., Pohl, R. O.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 19.02.1993; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: 360606 - Other Materials- Physical Properties- (1992-); 400201 - Chemical & Physicochemical Properties; ATOMS; Buckminsterfullerene; CARBON; Carbon allotropes; Circles; Climate; COLLECTIVE EXCITATIONS; Condensed matter: structure, mechanical and thermal properties; Conduction; CRYSTALS; Density; ELEMENTS; ENERGY-LEVEL TRANSITIONS; Exact sciences and technology; EXCITATION; FULLERENES; Graphite; Heat; Heat conduction; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LATTICE VIBRATIONS; MATERIALS; MATERIALS SCIENCE; MOLECULES; NONMETALS; Personality; PHYSICAL PROPERTIES; Physics; Scientific Concepts; SOLIDS; SPECIFIC HEAT; THERMAL CONDUCTIVITY; Thermal diffusivity; Thermal properties of condensed matter; Thermal properties of crystalline solids; THERMODYNAMIC PROPERTIES; Vibration; Specific heat; Temperature; Localized mode; Fullerenes; Atomic cluster; Thermal conductivity; Experimental study; Vibrational mode
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.259.5098.1145

Evidence is presented that the lattice vibrations of compacted C$_{60}$/C$_{70}$ fullerite microcrystals consist predominantly of localized modes. Vibrational motions of the rigid molecules ("buckyballs") have been identified as well as their internal vibrations. Debye waves play only a relatively minor role, except below ∼4 kelvin. By comparison with other crystalline materials, for these materials the Einstein model of the specific heat and thermal conductivity of solids, which is based on the assumption of atoms (in this case, buckyballs) vibrating with random phases, is in much better agreement with the measurements than the Debye model, which is based on collective excitations.