Hostname: page-component-7479d7b7d-qs9v7 Total loading time: 0 Render date: 2024-07-11T23:27:05.331Z Has data issue: false hasContentIssue false
  • English
  • Français

First-Principles Study of Soliton Hyperfine Interactions in Polyacetylene

Published online by Cambridge University Press:  26 February 2011

C. T. White ,
F. W. Kutzler ,
J. W. Mintmire  and
M. R. Cook
C. T. White
Affiliation:
Theoretical Chemistry Section, Naval Research Laboratory, Washington, DC 20375
F. W. Kutzler
Affiliation:
Department of Chemistry, Tennessee Technical University, Cookeville, TN 38505
J. W. Mintmire
Affiliation:
Theoretical Chemistry Section, Naval Research Laboratory, Washington, DC 20375
M. R. Cook
Affiliation:
Department of Chemical Engineering, University of Massachusetts, Amherst, MA 01003
Get access

Abstract

All-trans-polyacetylene is considered the prototypical broad band gap quasi onedimensional organic semiconductor. Intrinsicsoliton defects have long been known to be important to the understanding of the observed properties of this system at low doping levels. Magnetic resonance techniques provide powerful experimental probes into the nature and environment of these neutral-radical defects. In an earlier work we showed that firstprinciples spin-polarized local density functional (LDF) methods reliably predict proton Fermi-contact coupling constants for planar, neutral, organic π-radicals. We have also used these methods to calculate the Fermi-contact proton coupling constants associated with the soliton defect in polyacetylene.Herein we compare the results of these earlier soliton calculations to results from recent electron-nuclear double-resonance (ENDOR) experiments. Our predicted ratio of the negative to positive spin densities is in good agreement with these ENDORstudies. The negative spin densities arise from spin-polarization effects which are found to cause the soliton level at midgap to be split by several tenths of an eV.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 209: Symposium K – Defects in Materials , 1990 , 263
Copyright
Copyright © Materials Research Society 1991

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

REFERENCES

1. For a recent review, Heeger, see A.J. et al. , Rev. Mod. Phys. 60, 781 (1988) and references therein.CrossRefGoogle Scholar
2. Su, W.-P, Schrieffer, J.R., and Heeger, A.J., Phys. Rev. Lett. 42, 1698 (1979).CrossRefGoogle Scholar
3. Su, W.-P., Schrieffer, J.R., and Heeger, A.J., Phys. Rev. B 22, 2099 (1980).CrossRefGoogle Scholar
4. Carrington, See, e.g., A., Intrduction to Magnetic Resonance, (Harper and Row, New York, 1967), Chap. 6.Google Scholar
5. Slichter, See, e.g., C.P., Principles of Magnetic Resonance, (Harper and Row, New York, 1963), Chap. 7.Google Scholar
6. McConnell, H.M., J. Chem. Phys. 28, 188 (1958).Google Scholar
7. White, C.T., Kutzler, F.W., and Cook, M., Phys. Rev. Lett. 56, 252 (1986).CrossRefGoogle Scholar
8. Connolly, See, e.g., J.W.D., in Modern Theoretical Chemistry, edited by Segal, G.A. (Plenum, New York, 1976), Vol. 7, and references therein.Google Scholar
9. Rosen, A. et al. , J. Chem. Phys. 65, 3624 (1976);Google Scholar
9a. Ellis, D.E., and Painter, G.S., Phys.Rev. B 2, 2887 (1970).CrossRefGoogle Scholar
10. Thomann, H., et al. , Phys. Rev. Lett. 50, 533 (1983).CrossRefGoogle Scholar
11. Kuroda, S., and Shirakawa, H., Phys. Rev. B 35, 9380 (1987).CrossRefGoogle Scholar
12. Mehring, M. et al. , Synth. Metals 28, D399 (1989).CrossRefGoogle Scholar
13. Kutzler, F.W. and Ellis, D.E., J. Chem. Phys. 84, 1033 (1986).CrossRefGoogle Scholar
14. Kutzler, F. W., White, C.T., and Mintmire, J. W., Int. J. Quantum Chem. 29, 767 (1986).CrossRefGoogle Scholar
15. Subbaswamy, K.R. and Grabowski, M., Phys. Rev. B 24, 2168 (1981).CrossRefGoogle Scholar