Electrodeposition of diamondlike carbon films on nickel substrates
- PDF / 108,221 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 31 Downloads / 258 Views
Diamondlike carbon (DLC) films were electrodeposited on nickel substrates from a solution of acetylene in liquid ammonia at low temperature and low potential using a three-electrode cell. Raman spectra showed a shoulder D peak at 1365 cm−1 and a broad G peak at 1558 cm−1 for the films, indicating an sp3 and sp2 carbon mixture. The presence of a 1230 cm−1 peak also indicated some four-fold-coordinated bonds of microcrystalline diamond. Fitting of the peaks in the Raman spectra specified the electrodeposited films were hydrogenated amorphous alloys, a-C:H. X-ray photoelectron spectra also pointed to the films containing a mixture of sp3 and sp2 carbon. Fourier transform infrared spectra of the electrodeposited films had C-H stretching vibrations, which is consistent with hydrogenated DLC films.
I. INTRODUCTION
The properties of diamondlike carbon (DLC) films, such as high hardness, high thermal conductivity, chemical inertness, and corrosion resistance, make these materials attractive for use in a variety of technological fields. The deposition of DLC films was mainly accomplished by two methods: chemical vapor deposition and physical vapor deposition.1–3 Other low-cost methods for deposition of DLC films out of solutions at atmospheric pressure have been explored, such as electrolysis, electrophoresis, and electrodeposition.4 –24 The vast majority of the solution deposition of carbon and DLC films was done at high voltages (>1000 V) from organic solutions. Both direct current power and pulse-modulated power were used as energy sources in these experiments. This method has been used to deposit carbon and DLC films from a variety of organic solutions including methanol, acetonitrile, N,N-dimethylformamide, nitromethane, nitroethane, ethanol, and acrylonitrile.4 –19 All of these methods involve the use of very high potentials (1000–2000 V), which makes it difficult to control the deposition process and to study the mechanism. The only report of electrodepositing DLC films was done by Novikov and Dymont.21–23 Raman spectra of these films showed some weak bands characteristic of DLC and other unknown peaks. These were interpreted as a mixture of different forms of carbon but were not identified. The authors noted that experimental parameters
a)
Address all correspondence to this author. e-mail: [email protected] J. Mater. Res., Vol. 18, No. 7, Jul 2003
http://journals.cambridge.org
Downloaded: 19 Aug 2014
of the deposition method might affect the properties of these DLC films. An exploration of electrodeposition and the resulting films is important to understand how experimental parameters affect film properties and elucidation of the deposition mechanism. This study reports the electrodeposition of DLC films at both low temperature and low potential on nickel substrates from acetylene dissolved in liquid ammonia. The films were characterized by Raman spectroscopy, scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. II. EXPERIMENTAL
The wor
Data Loading...
