Solid State Communications 150 (2010) 311–315 Contents lists available at ScienceDirect Solid State Communications journal homepage: www.elsevier.com/locate/ssc Synthesis of multiwall carbon nanotubes by chemical vapor deposition of ferrocene alone Ravi Bhatia ∗ , V. Prasad Department of Physics, Indian Institute of Science, Bangalore-12, India article info Article history: Received 15 August 2009 Received in revised form 30 October 2009 Accepted 12 November 2009 by A. Pinczuk Available online 25 November 2009 Keywords: A. Carbon nanotube B. Chemical vapor deposition C. Electron microscopy D. Magnetic property abstract Multiwall carbon nanotubes (MWNTs) filled with Fe nanoparticles (NPs) have been synthesized by thermal chemical vapor deposition of ferrocene alone as the precursor. The MWNTs were grown at different temperatures: 980 and 800 ◦ C. Characterization of as-prepared MWNTs was done by scanning and transmission electron microscopy, and X-ray diffraction. The transmission electron microscopy study revealed that Fe NPs encapsulated in MWNTs grown at 980 and 800 ◦ C are spherical and rod shaped, respectively. Room-temperature vibrating sample magnetometer studies were done on the two samples up to a field of 1 T. The magnetization versus magnetic field loop reveals that the saturation magnetization for the two samples varies considerably, almost by a factor of 4.6. This indicates that Fe is present in different amounts in the MWNTs grown at the two different temperatures. © 2009 Elsevier Ltd. All rights reserved. 1. Introduction Carbon nanotubes (CNTs) are sp 2 hybridized molecular nanos- tructures, which are thought to be derived from fullerenes [1,2]. It is the unique and exceptional combination of mechanical and elec- trical properties, combined with their high length-to-diameter ra- tio (greater than 10 6 ), that make them an important material for future technology [3]. Attempts have been made to use CNTs in the fabrication of devices like field emission displays, field emit- ters, flow meters, batteries and carbon nanotube field effect tran- sistors [4–8]. These molecular nanostructures are proposed to be an efficient hydrogen storage material [9]. Carbon nanotube cylin- drical membranes have been reported to be used as filters for the elimination of multiple components of heavy hydrocarbons from petroleum and for the filtration of bacterial contaminants of size less than 25 nm from water [10]. Recently, CNT bundles have been proposed to be a good material for low-temperature sens- ing [11]. Arc discharge, laser ablation, chemical vapor deposition (CVD), etc., have been employed to produce CNTs [1,12,13]. Differ- ent precursors have been used to obtain different morphologies of the CNTs. Carbon sources in liquid phase like tetrahydrofuran, hex- ane, xylene, benzene, pyridine, etc., with ferrocene (FeCp 2 ) as a cat- alyst have been used for fabricating different architectures of CNTs ∗ Corresponding author. Tel.: +91 80 2293 2313; fax: +91 80 2360 2602. E-mail address: bhatia.phy@gmail.com (R. Bhatia). [14]. Some hydrocarbons in gaseous phase like methane, ethylene, acetylene, etc., have also been used to produce CNTs [15–17]. CVD is a popular method for the synthesis of CNTs due to its large scala- bility, low cost and lower processing temperature requirements. In earlier studies, the production of Fe nanoparticles (NPs) enclosed in carbon shells, carbon-encapsulated Fe 3 C NPs, metallic Fe and Fe 2 0 3 NPs had been reported by decomposition of FeCp 2 using dif- ferent methods such as the laser assisted CVD method, photolytic dissociation method, plasma production method, etc. [18–21]. In addition, an expensive and quite complicated approach, involving many steps, for the growth of CNTs by thermal decomposition of FeCp 2 has been reported [22]. In this paper we report on a simple one-step method of synthe- sizing MWNTs of fairly good quality and yield using FeCp 2 alone as the starting material. The synthesis technique adopted by us is simple and quite inexpensive ($ 200–300) in comparison to other reported methods. The advantage of using FeCp 2 alone is that the precursor acts as both the catalyst and carbon source material. Growth temperature is found to be one of the most important pa- rameters that greatly affects the magnetic properties of Fe-filled MWNTs. 2. Experimental details The schematic of the set-up employed for the synthesis of MWNTs is shown in Fig. 1. The whole apparatus consisted of a single-zone furnace attached with a temperature controller. A 0038-1098/$ – see front matter © 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.ssc.2009.11.023