Ultralow thermal conductivity of fullerene derivatives

TitleUltralow thermal conductivity of fullerene derivatives
Publication TypeJournal Article
Year of Publication2013
AuthorsWang, Xiaojia, C.D. Liman, N.D. Treat, M.L. Chabinyc, and David G. Cahill
Date PublishedAUG 21
AbstractRecently, Duda et al. [J. C. Duda, P. E. Hopkins, Y. Shen, and M. C. Gupta, Phys. Rev. Lett. 110, 015902 (2013)] reported that the fullerene derivative [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) has the lowest thermal conductivity Lambda ever observed in a fully dense solid, Lambda approximate to 0.03 W m(-1) K-1. We have investigated a variety of phases and microstructures of PCBM and the closely related compound [6,6]-phenyl-C61-butyric acid n-butyl ester (PCBNB) and find that the thermal conductivities of PCBM and PCBNB films are mostly limited to the range 0.05 < Lambda < 0.06 W m(-1) K-1 with a few samples having slightly higher Lambda. The conductivities we observe are approximate to 70% larger than reported by Duda et al. but are still ``ultralow'' in the sense that the thermal conductivity is a factor of approximate to 3 below the conductivity predicted by the minimum thermal conductivity model using an estimate of the thermally excited modes per molecule.