Dominant Cr3+ centers in LiNbO3 under hydrostatic pressure |
| |
Authors: | S A Basun A A Kaplyanskii A B Kutsenko V Dierolf T Tröster S E Kapphan K Polgar |
| |
Institution: | 1. Ioffe Physical-Technical Institute, St.-Petersburg, 194021, Russia 2. Fachbereich Physik, Universit?t-GH Paderborn, D-33095, Germany 3. Fachbereich Physik, Universit?t Osnabrück, D-49069, Germany 4. Research Institute for Solid State Physics and Optics, 1121, Budapest, Hungary
|
| |
Abstract: | Low-temperature luminescence spectra of stoichiometric Cr: LiNbO3 and of congruent Cr, Mg: LiNbO3 were studied. Cr3+ impurity ions preferentially occupy Li+ sites (CrLi) in the LiNbO3 crystal lattice, while Cr3+ ions substituting for Nb5+ ions (CrNb) occur in addition to CrLi centers in codoped Cr, Mg: LiNbO3 crystals. Application of a high hydrostatic pressure leads to a transformation of (dominant in concentration) Cr3+ centers from low-to high-crystal-field centers. Due to a strong pressure-induced blue shift of the 4 T 2 state resulting in crossing with the 2 E state, the replacement of the broad band 4 T 2 → 4 A 2 emission by a narrow R-line emission 2 E → 4 A 2 occurs in the luminescence spectra of the samples. This effect of level crossing was observed for the dominant Cr Li 3+ and Cr Nb 3+ centers at pressures which correlated well with estimations based on the 4 T 2-2 E energy gap (230 and 1160 cm?1) and on the rate of their pressure-induced change (14.35 and 11.4 cm?1/kbar, respectively). |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|