Interface thermal resistance is extremely important for heat transport in composite nanostructures. The micro interface resistance originated from phonon mismatch plays a significant role in nanostructures. It depends on various factors including microstructure of interfaces. In fact the interface thermal resistance is not an intrinsic property of nanostructures. This work investigates the influence of staggered atom replacements across interfaces on the effective in-plane thermal conductivity of a dual-layered composite film and a monolayer film using molecular dynamics (MD). A parameter, the staggered number density is defined which is the ratio of the number of staggered lattice sites across interface over the whole lattice sites on the interface plane. The effects of the staggered number density and the height of the staggered sites are investigated. An interesting result is that the effective in-plane thermal conductivity varies with the staggered number density non-monotonically. With increasing number density the conductivity first decreases and then increases. The thermal conductivity is found to decrease with increasing staggered height. The mechanism of these phenomena is discussed.
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