Excitonic two-phonon progressions in transition metal compounds
Evidence of two-phonon structures is reported for some intra-configurational crystal field transitions in layered V- and Cr-halides. In particular, the crystal field spectrum of CrBr 2 (3d 4) has been shown for the first time, since the exciton–phonon interaction, despite its unfilled e g orbitals,...
Saved in:
| Published in | Physics letters. A Vol. 277; no. 4; pp. 281 - 286 |
|---|---|
| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
Elsevier B.V
04.12.2000
|
| Online Access | Get full text |
Cover
Loading…
| Summary: | Evidence of two-phonon structures is reported for some intra-configurational crystal field transitions in layered V- and Cr-halides. In particular, the crystal field spectrum of CrBr
2 (3d
4) has been shown for the first time, since the exciton–phonon interaction, despite its unfilled e
g orbitals, vanishes to first order yielding a two-phonon sequence in the
3A
l(G)+
3A
2(F) band. It is suggested that the main mechanism for the occurrence of two-phonon progressions consists in the direct coupling of the incident photon to a two-phonon state via the second-order dipole moment operator. |
|---|---|
| ISSN: | 0375-9601 1873-2429 |
| DOI: | 10.1016/S0375-9601(00)00682-4 |