▎ 摘　　要

We present a theory for the lattice thermal conductivity kappa(L) of multilayer graphene (MLG) and graphite, which is based on an exact numerical solution of the Boltzmann equation for phonons. Dominant contributions to kappa(L) from out-of-plane or flexural phonons are found, which is consistent with previous findings for single-layer graphene (SLG). However, the interaction between graphene layers in MLG and graphite breaks a selection rule on phonon-phonon scattering, causing their kappa(L)s to be much lower than that of SLG. C-13 isotopes are shown to be an important scattering mechanism, accounting for an similar to 15% additional drop in the kappa(L) of these systems. We demonstrate that the kappa(L) values converge to that of graphite after only about five layers, a consequence of weak interlayer coupling. These findings are qualitatively consistent with recent measurements of kappa(L) for MLG.