Abstract
The optical spectroscopy of Cr3+ ions doped into near-stoichiometric LiNbO3 crystals, pure and co-doped with MgO, has been investigated. In the near-stoichiometric LiNbO3:Cr(0.2 mol%):Mg(2 mol%) crystal, the optical spectra resemble those previously observed for congruent LiNbO3:Cr:MgO samples when the total MgO content exceeds the 4.6 mol% threshold. The coexistence of two types of Cr3+ centre ([Cr]Li and [Cr]Nb) characterized the optical and luminescence spectra of this sample. The concentration equilibrium between the two types of centre is strongly displaced towards the [Cr3+]Nb centre, permitting us to obtain with accuracy the parameters of the broad bands. The R-line associated with the [Cr]Nb centre is only observable in the low-temperature emission spectrum. The Fano antiresonance lines present have been observed to be more pronounced for the near-stoichiometric samples than for congruent ones.
| Original language | English |
|---|---|
| Pages (from-to) | 281-290 |
| Number of pages | 10 |
| Journal | Journal of Physics: Condensed Matter |
| Volume | 15 |
| Issue number | 2 |
| Early online date | 20 Dec 2002 |
| DOIs | |
| Publication status | Published - 22 Jan 2003 |
Keywords
- chromium
- impurity absorption spectra
- impurity states
- lithium compounds
- luminescence
- magnesium