2002/12/24 by A. N. Aleksandrovskii, A. S Bakai, V. B. Esel’son +9 · 1 citation
Chemistry · Materials Science · Physics and Astronomy · #Fullerene Chemistry and Applications #Thermal Expansion and Ionic Conductivity #Thermal properties of materials #cond-mat.dis-nn #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/1.1542477
published as A.N. Aleksandrovskii, A.S Bakai, A.V. Dolbin, V.B. Esel'son, G.E. Gadd, V.G. Gavrilko, V.G. Manzhelii, S. Moricca, B. Sundqvist, B.G. Udovidchenko, Fiz.Nizk.Temp. 29, 432-442, (April 2003) · 18 pages, 12 figures
arxiv created 2002/12/24 · openalex publication_date 2003/04/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The low-temperature (2–24 K) thermal expansion of pure (single-crystal and polycrystalline) C60 and polycrystalline C60 intercalated with He, Ne, Ar, and Kr is investigated using a high-resolution capacitance dilatometer. The investigation of the time dependence of the sample length variations ΔL(t) on heating by ΔT shows that the thermal expansion is determined by the sum of positive and negative contributions, which have different relaxation times. The negative thermal expansion usually prevails at helium temperatures. The positive expansion is connected with the phonon thermalization of the system. The negative expansion is caused by reorientation of the C60 molecules. It is assumed that the reorientation is of a quantum character. The inert gas impurities affect the reorientation of the C60 molecules very strongly, especially at liquid-helium temperatures. A temperature hysteresis of the thermal expansion coefficient of Kr– and He–C60 solutions is revealed. The hysteresis is attributed to orientational polymorphous transformation in these systems.