| AVS 55th International Symposium & Exhibition | |
| Advanced Surface Engineering | Wednesday Sessions |
| Session SE+NC-WeA |
| Session: | Hard and Nanocomposite Coatings: Synthesis, Structure, and Properties II |
| Presenter: | E. Broitman, Carnegie Mellon University |
| Authors: | E. Broitman, Carnegie Mellon University A. Furlan, Linköping University, Sweden G.K. Gueorguiev, Linköping University, Sweden Zs. Czigány, Research Institute for Technical Physics and Materials Science, Hungary A.J. Gellman, Carnegie Mellon University S. Stafström, Linköping University, Sweden L. Hultman, Linköping University, Sweden |
| Correspondent: | Click to Email |
Amorphous phosphorous-carbide films have been considered as a new tribological coating material with unique electrical properties. However, the coatings cannot be practically used until now because CPx films rapidly oxidize/hydrolyze and delaminate when in contact with air. Recently we demonstrated that CPx thin solid films with a fullerene-like structure can be deposited by magnetron sputtering. Thus, the introduction of P atoms in the graphene structure induces the formation of bent and interlinked grapheme planes.1,2 In this work we compare the uptake of water of amorphous phosphorous-carbide (a-CPx) films, with fullerene-like phosphorous-carbide (FL-CPx) and amorphous carbon (a-C) films. Films with thickness in the range 10-300 nm were deposited on quartz crystal substrates by reactive DC magnetron sputtering. The film microstructure was characterized by X-ray photoelectron spectroscopy, and transmission electron microscopy and diffraction. A quartz crystal microbalance placed in a vacuum chamber as described in3 was used to measure their water adsorption. Measurements indicate that the amount of adsorbed water is highest for the pure a-C films and that the FL-CPx films adsorbed less water than a-CPx. To provide additional insight into the atomic structure of defects in the FL-CPx, a-CPx and a-C compounds, we performed first-principles calculations within the framework of Density Functional Theory. Emphasis was put on the energy cost for formation of vacancy defects and dangling bonds in relaxed systems.4 Cohesive energy comparison reveals that the energy cost formation for dangling bonds in different configurations is considerable higher in FL-CPx than for the amorphous films. These simulations thus confirm the experimental results that dangling bonds are less likely in FL-CPx than in a-CPx and a-C films.
1 A. Furlan, G.K. Gueorguiev, Zs. Czigány, H. Högberg, S. Stafström, and L. Hultman, Phys. Stat. Solidi Rapid Research Letters (2008) in press
2 G.K. Gueorguiev, A. Furlan, H. Högberg, S. Stafström, and, L Hultman, Chem. Phys. Lett. 426 (2006) 374
3 E. Broitman, VV. Pushkarev, A.J. Gellman, J. Neidhardt, A. Furlan, and L. Hultman, Thin Solid Films 515 (2006) 979
4 E. Broitman, G. K. Gueorguiev, A. Furlan, N. T. Son, A.J. Gellman, S. Stafstrom, and L. Hultman, ICMCTF, San Diego, CA (May 2008).