Isotope Effect on the Thermal Conductivity of Boron Nitride Nanotubes

Abstract

We have measured the temperature-dependent thermal conductivity kappa(T) of individual multiwall boron nitride nanotubes using a microfabricated test fixture that allows direct transmission electron microscopy characterization of the tube being measured. kappa(T) is exceptionally sensitive to isotopic substitution, with a 50% enhancement in kappa(T) resulting for boron nitride nanotubes with 99.5% 11B. For isotopically pure boron nitride nanotubes, kappa rivals that of carbon nanotubes of similar diameter.

Thermal Conductivity and Phonon Transport in Suspended Few-Layer Hexagonal Boron Nitride

“…Interestingly, both samples measured here maintain higher thermal conductivity than that reported for a multiwalled h-BN nanotube, which was measured with a different micro-bridge device without eliminating the contact thermal resistance. 23 To understand the thermal conductivity suppression at low temperatures, we first evaluate the impact of phonon scattering by the lateral edges of the h-BN ribbon and by point defects. We have calculated the thermal conductivity of the suspended h-BN according to a solution of the phonon Boltzmann transport equation, 19 (1) Without accounting for scattering by polymer residues and Umklapp scattering, the latter of which is negligible at low temperatures, the calculated thermal conductivity shows good agreement with the measurement results at temperatures below 100 K when l b is taken to be 550 nm and 180 nm for the 11 and 5 layer h-BN samples, respectively (See Supporting Information).…”

Thermal transport in nanostructures

“…Later, this large reduction by isotopic doping effect has been confirmed experimentally. 63 Zhang and Li calculated the temperature dependence of thermal conductivity of (5,5) single-wall carbon nanotubes (SWCNTs). 45 Fig.…”

Young’s modulus of graphene: A molecular dynamics study

“…The thermal conductivity has been shown to be very sensitive to the isotopic disorder percentage in the low disorder region with more than 40% reduction of thermal conductivity by less than 5% isotopic disorder percentage; while for higher disorder percentage, the thermal conductivity keeps almost unchanged. 24,25,26 So the thermal conductivity can be greatly enhanced by synthesizing isotopically pure nanotubes. 26 In conclusion, we have used MD to obtain the thermal vibration of graphene and then calculated the Young's modulus from the thermal mean-square vibration amplitude.…”

“…24,25,26 So the thermal conductivity can be greatly enhanced by synthesizing isotopically pure nanotubes. 26 In conclusion, we have used MD to obtain the thermal vibration of graphene and then calculated the Young's modulus from the thermal mean-square vibration amplitude. The advantage of this approach is that we don't have to introduce external strain on the system, and it can be easily applied to study different effects on the Young's modulus.…”