Site-selective growth of multi-walled carbon nanotubes (MWCNTs) from an iron oxide nanoparticle catalyst patterned by drying-mediated self-assembly technique is present. The ethanol solution of the iron nitrate was employed as catalyst precursor. The catalyst precursor was mounted on silicon wafer by dip-coating. After evaporation of solvent at room temperature, the catalyst pattern formed. The catalyst pattern was employed to synthesize carbon nanotube pattern by chemical vapor deposition of ethanol vapor after oxidation of iron nitrate. The patterned array of MWCNTs was obtained with a dot size of around 5 'm and the distance of about 25 'm. The present method offers a simple and cost-effective method to grow carbon nanotubes with self-assembled patterns.
A simple thermal chemical vapor deposition (STCVD) growth technique of multi-walled carbon nanotubes (MWCNTs) is present. Carbon nanotube film was synthesized on the Pt plate substrates by pyrolysis of ethyl alcohol as carbon source at lower reaction temperature at atmospheric pressure by using simple apparatus. The as-synthesized MWCNTs were characterized by both scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The electrical property of an individual MWCNT was evaluated by I-V measurement. The electrical resistance of single MWCNT is about 450 k/ in linear region under bias voltage between 2 to 4 V. It can undergo a large current of 6 2A at 4 V
In order to meet the requirements of various applications, considerable efforts have been focused on the new approaches for synthesizing carbon nanotubes. Recently, simple thermal chemical vapor deposition growth technique by pyrolyzing ethyl alcohol has been developed. However, this method needs metallic catalyst. Here, we demonstrate that it is possible to synthesize multi-walled carbon nanotubes without the aid of any catalyst. The as-synthesized products were analyzed by high-resolution transmission electron microscopy (HRTEM). The HRTEM images show that the products are straight multi-walled carbon nanotubes. The synthesis technique of carbon nanotubes is cost-effective because of the catalyst-free process.
This letter reports on the measurements of the in-plane thermal conductivity and the electrical conductivity of a microfabricated, suspended, nanosized platinum thin film with the width of 260nm, the thickness of 28nm, and the length of 5.3μm. The experimental results show that the electrical conductivity, the resistance-temperature coefficient and the in-plane thermal conductivity of the nanofilm are greatly lower than the corresponding bulk values from 77to330K. The comparison results indicate that the relation between the thermal conductivity and the electrical conductivity of this nanofilm might not follow the Wiedemann–Franz law that describes the relation between the thermal conductivity and the electrical conductivity of a bulk metallic material.
In this letter, a simple thermal chemical vapor deposition growth technique of multi-walled carbon nanotubes (MWCNTs) are present. Aligned carbon nanotube arrays were grown on the Fe2O3/SiO2/Si substrates by pyrolysis of ethanol as carbon source at lower reaction temperature at atmospheric pressure by using a simple apparatus. The as-synthesized MWCNTs were characterized by both scanning electron microscopy and high-resolution transmission electron microscopy. The electrical property of an individual MWCNT was evaluated by I–V measurement. The electrical resistance of single MWCNT of 0.6μm long is about 330kΩ in linear region under bias voltage between 2.5 and 4.5V. It can undergo a large current of 7μA at 4.5V.