Size and temperature dependence of the specific heat capacity of carbon nanotubes

Abstract

The specific heat capacity ( C v ) of carbon nanotubes for different temperatures and radii is calculated and presented. These calculations are based upon the continuum model of Zhang et al. The change in dimensionality behaviour (from quasi-1D to quasi-2D) as a function of temperature for tubes of different radii is investigated. It is found that for a range of radii the changeover occurs between 180 K and 400 K. Thicker nanotubes have intrinsically stronger quasi-2D behaviour beyond this temperature range than thinner nanotubes. The present numerical results confirm a qualitative discussion of this behaviour presented earlier by Benedict et al. For a given temperature, the variation of C v as a function of radius is also discussed. An expression has been obtained to show the linear variation of C v in the appropriate low temperature region.