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Theoretical Prediction and Experimental Confirmation of Charge Transfer Vibronic Excitons and Their Phase in ABO3 Perovskite Crystals

Published online by Cambridge University Press:  01 February 2011

R. I. Eglitis ,
V. S. Vikhnin ,
E. A. Kotomin ,
S. E. Kapphan  and
G. Borstel
R. I. Eglitis
Affiliation:
Department of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany
V. S. Vikhnin
Affiliation:
Department of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany
E. A. Kotomin
Affiliation:
Department of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany Institute of Solid State Physics, University of Latvia, 8 Kengaraga str., Riga LV-1063, Latvia
S. E. Kapphan
Affiliation:
Department of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany
G. Borstel
Affiliation:
Department of Physics, University of Osnabrueck, D-49069 Osnabrueck, Germany
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Abstract

The current theoretical and experimental knowledge of new polaronic-type excitons in ferroelectric oxides - charge transfer vibronic excitons (CTVE) is discussed. It is shown that quantum chemical Hartree-Fock-type calculations using a semiempirical Intermediate Neglect of Differential Overlap (INDO) method (modified for ionic/partly ionic solids) as well as photoluminescence studies in ferroelectric oxygen-octahedral perovskites confirm the CTVE existence. Our INDO calculations for KTaO3 and KNbO3 have demonstrated that the triplet exciton is a triad centre containing one active O atom and two Ta atoms sitting on the opposite sites from this O atom. The total energy of a system is lowered by the combination of Coulomb attraction between electron and hole and the vibronic effect in this charge transfer vibronic exciton. It is shown by means of our INDO calculations that polaronic-type CTVE in ferroelectric oxides could lead to the formation of a new crystalline phase. The ground state energy of this phase consisting of strongly correlated CTVEs lies within an optical gap of a pure crystal, and is characterized by a strong tetragonal lattice distortion, as well as by the ferroelectric ordering.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 718: Symposium D – Perovskite Materials , 2002 , D10.32
Copyright
Copyright © Materials Research Society 2002

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References

1. Agranovich, V.M., and Zakhidov, A.A., Chem. Phys. Lett. 50, 278 (1977).Google Scholar
2. Reineker, P., and Yudson, V.I., Phys. Rev. B 63, 233101 (2001).Google Scholar
3. Devreese, J.T., in Encyclopedia of Applied Physics, ed. by Trigg, G.L. (VCH Publishers, weinheim, 1996), Vol. 14, p. 383.Google Scholar
4. Maglione, M., in Defects and Surface-Induced Effects in Advanced Perovskites, ed. by Borstel, G. (Kluver Academic Publishers, Boston, 2000), Vol. 77, p. 27.Google Scholar
5. Vikhnin, V.S., Ferroelectrics 199, 25 (1997).Google Scholar
6. Vikhnin, V.S., Liu, H., Jia, W., Kapphan, S.E., Eglitis, R.I., and Usvyat, D., J. Luminescence 83-84, 109 (1999).Google Scholar
7. Kotomin, E.A., Eglitis, R.I., and Borstel, G., J. Phys.: Condens. Matter 12, L557 (2000).Google Scholar
8. Eglitis, R.I., Kotomin, E.A., and Borstel, G., Comput. Mater. Sci. 21, 530 (2001).Google Scholar
9. Vikhnin, V., Ferroelectrics Letters 25, 27 (1999).Google Scholar
10. Cohen, R.E., Nature 358, 136 (1992).Google Scholar
11. Cohen, R.E., and Krakauer, H., Phys. Rev. B 42, 6416 (1990).Google Scholar
12. Zhong, W., Vanderbilt, D., and Rabe, K.M., Phys. Rev. Lett. 74, 4067 (1995).Google Scholar
13. Rabe, K.M., and Waghmare, U.V., J. Phys. Chem. Solids 57, 1397 (1996).Google Scholar
14. Rabe, K.M., and Waghmare, U.W., Phys. Rev. B 52, 13236 (1995).Google Scholar
15. Pople, J.A., and Beveridge, D.L., Approximate Molecular Orbital Theory (New York: McGraw-Hill, 1970).Google Scholar
16. Stefanovich, E., Shidlovskaya, E., Shluger, A., and Zakharov, M., Phys. Stat. Solidi B 160, 529 (1990).Google Scholar
17. Shluger, A.L., and Stefanovich, E., Phys. Rev. B 42, 9664 (1990).Google Scholar
18. Stashans, A., and Kitamura, M., Solid State Commun. 99, 583 (1996).Google Scholar
19. Eglitis, R.I., Postnikov, A.V., and Borstel, G., Phys. Rev. B 54, 2421 (1996).Google Scholar
20. Eglitis, R.I., Postnikov, A.V., and Borstel, G., Phys. Rev. B 55, 12976 (1997).Google Scholar
21. Vikhnin, V.S., Eglitis, R.I., Markovin, P.A., and Borstel, G., Phys. Stat. Solidi B 212, 53 (1999).Google Scholar
22. Eglitis, R.I., Kotomin, E.A., and Borstel, G., J. Phys.: Condens. Matter 12, L431 (2000).Google Scholar
23. Eglitis, R.I., Christensen, N.E., Kotomin, E.A., Postnikov, A.V., and Borstel, G., Phys. Rev. B 56, 8599 (1997).Google Scholar
24. Kotomin, E.A., Eglitis, R.I., Postnikov, A.V., Borstel, G., and Christensen, N.E., Phys. Rev. B 60, 1 (1999).Google Scholar
25. Vikhnin, V.S., Eglitis, R.I., Kapphan, S.E., Kotomin, E.A., and Borstel, G., Europhys. Lett. 56, 702 (2001).Google Scholar
26. Vikhnin, V.S., Kapphan, S., and Seglins, J., Rad. Eff. Def. Sol. 150, 109 (1999).Google Scholar
27. Vikhnin, V.S., Z. Phys. Chem. 201, 201 (1997).Google Scholar
28. Vikhnin, V.S., and Kapphan, S., Ferroelectrics 233, 77 (1999).Google Scholar
29. Vikhnin, V.S., Kislova, I.L., Kutsenko, A.B., and Kapphan, S.E., Solid State Commun. 121, 83 (2002).Google Scholar
30. Lehnen, P., Dec, J., Kleeman, W., Woike, Th., and Pankrath, R., Ferroelectrics 240, 281 (2000).Google Scholar
31. Vikhnin, V.S., Blinc, R., and Pirc, R., Ferroelectrics 240, 355 (2000).Google Scholar
32. Vikhnin, V.S., and Leyderman, A., Ferroelectric Letters 28, 155 (2001).Google Scholar
33. Vikhnin, V.S., Liu, G.K., Beitz, J.V., Phys. Lett. A 287, 419 (2001).Google Scholar