Temperature dependence of heat conduction coefficient in nanotube/nanowire networks**Project supported by the National Natural Science Foundation of China (Grant Nos. 11135001 and 11375066) and the National Basic Research Program of China (Grant No. 2013CB834100).

Abstract

Studies on heat conduction are so far mainly focused on regular systems such as the one-dimensional (1D) and two-dimensional (2D) lattices where atoms are regularly connected and temperatures of atoms are homogeneously distributed. However, realistic systems such as the nanotube/nanowire networks are not regular but heterogeneously structured, and their heat conduction remains largely unknown. We present a model of quasi-physical networks to study heat conduction in such physical networks and focus on how the network structure influences the heat conduction coefficient κ. In this model, we for the first time consider each link as a 1D chain of atoms instead of a spring in the previous studies. We find that κ is different from link to link in the network, in contrast to the same constant in a regular 1D or 2D lattice. Moreover, for each specific link, we present a formula to show how κ depends on both its link length and the temperatures on its two ends. These findings show that the heat conduction in physical networks is not a straightforward extension of 1D and 2D lattices but seriously influenced by the network structure.