Experimental heat capacity of 1D chains of Xe atoms adsorbed in the grooves of c-SWCNTs bundles: Contributions of vibrations and spatial redistribution of atoms

Abstract

In the temperature range of 2−75 K, the analysis and comparison were performed: (i) experimental CP,Xe(T) and theoretical CV,Xe(T) heat capacity of 1D chains of xenon atoms adsorbed in grooves on the outer surface of bundles of single-walled carbon nanotubes with closed ends (c-SWCNTs); (ii) the experimental heat capacity CP,Xe(T) and the experimental contribution to the radial thermal expansion of the c-SWNTs-Xe sample of Xe that adsorbed the grooves of c-SWCNTs [αXe(T)]. There is an anomaly near 60 K on the CP,Xe(T) and αXe(T) curves due to the contribution of the spatial redistribution of Xe atoms between the chains and the outer surface of c-SWNTs. It was found that the dependencies of CP,Xe(T) and αXe(T) are qualitatively similar below 60 K. The anomaly near 60 K in the CP,Xe(T) curve indicates the complete of fragmentation of 1D Xe atomic chains. The obtained result is important for understanding the kinetics of gas impurity sorption/desorption processes in c-SWNTs.