The impurity ion off-center behavior induced by a localized vibronic Frenkel exciton in a soft-mode crystal
Journal Article
·
· Crystallography Reports
- Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)
The 3d-4p Frenkel exciton localized at a Mn{sup 4+} impurity ion in BaTiO{sub 3} is considered. The electron and hole of this exciton are correlated, degenerate, and involved in the pair Jahn-Teller effect. Such an exciton is characterized by the significant contribution of indirect electron-hole attraction through lattice (in particular, soft) vibrations to the coupling energy, which is comparable with the Coulomb attraction. Thus, the exciton under consideration is both Coulomb and vibronic excitation. The vibronic contribution increases when approaching the point of soft phonon condensation. It is shown that a vibronic Frenkel exciton allows the off-center behavior of an impurity ion, which is significantly enhanced when approaching the point of soft phonon condensation. As a result, the vibronic Frenkel exciton is a low-lying excitation.
- OSTI ID:
- 22050827
- Journal Information:
- Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 3 Vol. 54; ISSN 1063-7745; ISSN CYSTE3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Core excitons and vibronic coupling in diamond and graphite
Vibronic exciton model for low bandgap donor–acceptor polymers
Journal Article
·
Sun Nov 28 23:00:00 EST 1993
· Physical Review Letters; (United States)
·
OSTI ID:5303229
Vibronic exciton model for low bandgap donor–acceptor polymers
Journal Article
·
Mon Dec 21 19:00:00 EST 2020
· Journal of Chemical Physics
·
OSTI ID:1853426