IFIBA   22255
INSTITUTO DE FISICA DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
A specific heat anomaly in multiwall carbon nanotubes as a possible sign of orientational order- disorder transition
Autor/es:
2. G. A JORGE.; V. BEKERIS; M. M ESCOBAR; S. GOYANES; D. ZILLI; A. L. CUKIERMAN; R. J CANDAL,
Revista:
CARBON
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2010 vol. 48 p. 525 - 530
ISSN:
0008-6223
Resumen:
We present micro-calorimetric specific heat measurements on different multiwall carbon
nanotubes of large outer diameter, as a function of temperature in the range 10120 K. A
clear anomaly at 60 K with the shape of a peak is present in two of the samples, and both
the height and the characteristic temperature of the peak are independent of magnetic field
and do not exhibit thermal hysteresis, discarding magnetic degrees of freedom related to Fe
seeds or contributions from adsorbed gases. These features suggest that the anomaly may
be caused by a structural change. As the anomaly is also unaffected by induced intertube
disorder, it may be related with a melting of orientational dislocations of individual tubes
within multiwall nanotubes, an effect that was theoretically predicted to occur in carbon
nanotubes and represents a distinctive feature of asymmetric molecular systems.