Thin films of C60 peapods and double wall carbon nanotubes

Thin films of SWCNTs were prepared from toluene suspension of single wall carbon nanotubes. The material was dropped on silicon and platinum surfaces with a controlled thickness. Filling with C60 and DWCNT – transformation of the films was performed. Multifrequency Raman spectroscopy was used to follow the peapod formation process and double wall transformation of the tubes. An efficient filling with C60 and DWCNT – transformation of the films was observed on platinum surface. Silicon reacts with carbon nanotubes forming SiC at the high temperature of the DWCNT formation, 1270 °C. The studies demonstrate the possibility for DWCNT formation process on individual tubes. In addition, it enables the production of homogeneous DWCNT films for several applications such as e.g. field emission devices. INTRODUCTION Since their discovery in 1991, carbon nanotubes (CNT) have attracted a lot of interest in the scientific community [1] due to their unique structural and electronic properties. Recently it was discovered that the C60 molecules can be combined with the single wall carbon nanotubes (SWCNTs) to forme the so-called peapods (C60 @ SWCNT) [2]. Annealing the peapods at high temperatures for several hours, in dynamic vacuum yields double wall carbon nanotubes (DWCNTs) [3] without any additional catalyst. Also, it has been shown that inner tubes formed by the fused C60 molecules inside the SWCNTs are higly defect free [4]. We show in the following that thin films of SWCNTs can be produced on different surfaces such as silicon and platinum. The filling with C60 fullerene and the transformation to DWCNTs is characterized using Raman spectroscopy. The study of the possible reaction between carbon nanotubes and different surfaces is also of practical interest. The aim of this work is to produce double wall carbon nanotube thin films for application devices, to study individual DW tubes, and to investigate possible reactions between carbon nanotubes and different substrates which is important for nanoreactor devices. A simple shema of a possible nanoreactor which uses the interior of a CNT as a “nanoclean room” to produce defect free, C60 based inner tubes is depicted below, in Fig 1. CP723, Electronic Properties of Synthetic Nanostructures, edited by H. Kuzmany et al. © 2004 American Institute of Physics 0-7354-0204-3/04/$22.00 273 Downloaded 28 Nov 2007 to 131.130.1.18. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/proceedings/cpcr.jsp