Посилання:The specific heat and the radial thermal expansion of bundles of single-walled carbon nanotubes / M.I. Bagatskii, M.S. Barabashko, A.V. Dolbin, V.V. Sumarokov // Физика низких температур. — 2012. — Т. 38, № 6. — С. 667-673. — Бібліогр.: 51 назв. — англ.
Підтримка:The authors are grateful to Profs. V.G. Manzhelii, B.A.
Danilchenko, E.S. Syrkin and S.B. Feodosyev for helpful
discussions. Thanks are also due to V.B. Eselson and S.I.
Popov for their assistance in the experiment.
The specific heat at constant pressure C(T) of bundles of single-walled carbon nanotubes (SWNTs) closed at
their ends has been investigated in a temperature interval of 2–120 K. It is found that the curve C(T) has features
near 5, 36, 80, and 100 K. The experimental results on the C(T) and the radial thermal expansion coefficient
αR(T) of bundles of SWNTs oriented perpendicular to the sample axis have been compared. It is found that the
curves C(T) and αR(T) exhibit a similar temperature behavior at T > 10 K. The temperature dependence of the
Grüneisen coefficient γ(T) has been calculated. The curve γ(T) also has a feature near 36 K. Above 36 K the
Grüneisen coefficient is practically independent of temperature (γ ≈ 4). Below 36 K γ(T) decreases monotonically
with lowering temperature and becomes negative at T < 6 K.