Carbon nanoscrolls on the surface of nanocrystalline graphite and diamond films
- PDF / 1,060,373 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 25 Downloads / 176 Views
MATERIALS, CERAMICS
Carbon Nanoscrolls on the Surface of Nanocrystalline Graphite and Diamond Films N. O. Skovorodnikova, S. A. Malykhina, F. T. Tuyakovab, R. R. Ismagilova, and A. N. Obraztsova a
b
Faculty of Physics, Moscow State University, Moscow, 119991 Russia Moscow State Technical University of Radio Engineering, Electronics, and Automation, pr. Vernadskogo 78, Moscow, 119454 Russia e-mail: [email protected] Received June 17, 2014
Abstract—Nanocrystalline graphite and diamond films with needlelike nanostructures on their surface have been obtained by plasma-enhanced chemical vapor deposition. According to the experimental data, these aggregates have the same nature for films of both types: they are tubular carbon nanoscrolls with a polygonal cross section. Nanoscrolls are formed by a helically folded graphene sheet; they look like twisted prisms. The needlelike prismatic structures have an average diameter in the range of 50‒500 nm, and their length reaches several micrometers. Possible mechanisms of formation of carbon nanostructures are discussed. DOI: 10.1134/S1063774515030177
INTRODUCTION Carbon nanostructures attract much attention of researchers dealing with nanotechnologies [1]. Wellknown examples of carbon nanostructures are graphene, nanotubes, and fullerenes. There are other, lesser known forms of nanocarbon materials, interest in which continuously increases, mainly due to their unique chemical and physical properties and diverse potential applications [2–6]. In particular, the possibility of using carbon nanotubes and nanostructured diamond films as field-emission cold cathodes is very attractive. For example, it was shown in [7] that the presence of needlelike aggregates with graphitelike conducting properties on the surface of nanodiamond film leads to a significant increase in its field-emission efficiency. Currently, various methods are used to fabricate nanocarbon materials. One of the most promising is the plasma-enhanced method of forming film materials by depositing carbon from a gas medium activated by a dc discharge [6‒10]. It was shown previously that this method provides a wide variety of carbon materials: from polycrystalline diamond films to films consisting of single- and multilayer graphene or graphitelike material in the form of graphite nanocrystallites or carbon nanotubes [11]. In particular, film materials containing needlelike twisted prismatic carbon nanoscrolls (TPCNs) were developed in [8]. Based on electron microdiffraction data obtained by transmission electron microscopy, some structural and morphological features of TPCNs were determined in order to develop their structural model.
In this study we obtained for the first time direct experimental data confirming the possibility of forming scroll-type prismatic tubular structures. These structures were formed for the first time on nanodiamond films. Our study showed their identity with similar aggregates observed in composition of nanographite films. EXPERIMENTAL All samples of nanocarbon materials were obtain
Data Loading...
