Scanning atom probe study of carbon nanotubes and graphite nanofibers with hydrogen terminated defects

Abstract

Graphite nanofibers (GNF) and multi-wall carbon nanotubes (MWCNT) are mass analyzed utilizing the unique capability of the scanning atom probe. Various clusters of carbon and hydrogen are detected from MWCNT. These are mostly H +, H2+, C+, CH3+ and C2H5+. Few cluster ions are detected for the mass rang of 100 - 300. The largest mass peak is C 28H4+ with two satellite mass peaks. The abundance of the satellites well agrees with the expected abundance of 12C2713CH4 and 12C 2613C2H4, 28% and 4%, respectively. No H+ mass peak was found for GNF but the significant number of the ions such as C2H5+, C3H 7+and C4H9+ are detected. These ions are detected at the beginning of the mass anal sis. After the removal of the surface layer, the detection rate of the largest cluster, C 23H2, increases. The proposed structure of the C 28H4 cluster is a rectangle formed three rows by three rows of hexagonal cells and that of C23H2 is the triangularly arranged six hexagonal cells. Four carbon atoms of C 28H4 and two carbon atoms of C23H2 clusters are terminated by hydrogen. © 2008 IOP Publishing Ltd.