Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-09T14:15:36.166Z Has data issue: false hasContentIssue false
  • English
  • Français

Atomic Bonding in Amorphous Alloys Based on Carbon, Nitrogen, and Hydrogen: A Thermodynamic Approach

Published online by Cambridge University Press:  10 February 2011

H. Efstathiadis ,
Z. Akkerman  and
F. W. Smith
H. Efstathiadis
Affiliation:
Physics Department, City College of New York, New York, NY 10031.
Z. Akkerman
Affiliation:
Physics Department, City College of New York, New York, NY 10031.
F. W. Smith
Affiliation:
Physics Department, City College of New York, New York, NY 10031.
Get access

Abstract

A thermodynamic model previously outlined for the prediction of the bonding in amorphous hydrogenated carbon-nitrogen alloy films (a-CxNyHz), is extended here to include the effects of enthalpy and entropy. Predictions are presented for the bonding of tetrahedral C(sp3), trigonal C(sp2), pyramidal N(sp3), and trigonal N(sp2) atoms in the alloy as well as the bonding of H to these atoms. When bond energies alone are considered, it is predicted that typical a-CxNyHz films will undergo a phase separation into graphitic regions containing C(sp2) atoms, and C(sp2)-N(sp3)-H groups, and diamond-like or polymeric regions containing only C(sp3) and H atoms. When the effects of entropy are also included, phase separation is eliminated and C(sp3)-C(sp2), C(sp2)=N(sp2), and C(sp2)-N(sp2), bonds are also predicted to be present. The model predictions are compared with experimental results for typical amorphous a-CxNyHz alloys that have been prepared via plasma-enhanced chemical vapor deposition from mixtures of nitrogen and acetylene. In a film with y=0.07 the carbon atoms sp3/sp2 ratio is predicted to be 0.7, while 80% of N atoms are predicted to be trigonal N(sp2) atoms.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 446: Amorphous and Crystalline Insulating Thin Films–1996 , 1996 , 395
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Liu, A. and Cohen, M., Science 245, 841 (1989).Google Scholar
2 Liu, C., Lu, Y. and Liebert, C., Science 261, 335 (1993)Google Scholar
3 Grill, A., Patel, V, and Meyerson, B. S., J. Mater. Res. 5, 2531 (1990).Google Scholar
4 Dischler, B., Bubenzer, A., and Koidl, P., Appl. Phys. Lett. 42, 636 (1983).Google Scholar
5 Kaufman, J., Metin, S., and Saperstein, D., Phys. Rev. B 39 13053 (1989).Google Scholar
6 Franceschini, D., Freire, F. and Silva, S., Appl. Phys. Lett. 68, 2645 (1996); D. Franceschini, C. Achete and F. Freire, Appl. Phys. Lett. 60, 3229 (1992).Google Scholar
7 Amir, O. and Kalish, R., J. Appl. Phys. 70, 4958 (1991).Google Scholar
8 Efstathiadis, H., Yin, Z. and Smith, F. W., Phys. Rev. B 46, 13119 (1992).Google Scholar
9 Efstathiadis, H., Akkerman, Z. and Smith, F. W., J. Appl. Phys. 79, 2954 (1996).Google Scholar
10 Efstathiadis, H., Akkerman, Z. and Smith, F. W., Mat. Res. Soc. Symp. Proc. 415, 51 (1996).Google Scholar
11 Bedford, A. F., Edmonson, P. B. and Mortimer, C. T., J. Chem. Soc. III, 2927 (1962).Google Scholar
12 Schwan, J., Dworschak, W., Jung, K. and Ehrhardt, H., Diamond and Related Materials 3, 1034(1994).Google Scholar
13 Efstathiadis, H., Akkerman, Z. and Smith, F. W. (unpublished).Google Scholar
14 Liu, A. and Cohen, M., Phys. Rev. B 39, 1760 (1989); Z. Akkerman, H. Efstathiadis and F. W. Smith, Mat. Res. Soc. Symp. Proc. 410, 217 (1996).Google Scholar
15 Cohen, M, Science 261, 307 (1993); K. Yu, M Cohen, et. al., Phys. Rev. B 49, 5034 (1994).Google Scholar