Thermal expansion coefficient in single-walled carbon nanotube bundles was determined as (formula presented) for the tube diameter and (formula presented) for the triangular lattice constant by means of x-ray scattering between 300 K to 950 K. The value for the intertube gap was (formula presented) which is larger than (formula presented) for the c-axis thermal expansion in graphite. The results reveal the presence of a remarkably larger lattice anharmonicity in nanotube bundles than that of graphite. The small value for the tube diameter is consistent with the seamless tube structure formed by a strong covalent bond between carbon atoms comparable to that in graphite.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2001|