Chromium Recharging Processes in the Y3Al5O12: Mg, Cr Single Crystal under the Reducing and Oxidizing Annealing Influence
Abstract
The influence of reducing and oxidizing annealing on optical absorption spectra of the yttrium aluminium garnet (YAG) single crystal co-doped with Mg and Cr is investigated using step-by-step isothermal and isochronous thermal treatment in H2 or air flow. The changes in the spectra were analyzed using decomposition on elementary absorption bands of Gaussian shape. The separated absorption bands attributed to the Cr(4+) ions occupying octahedral and tetrahedral sites in garnet lattice demonstrate different behaviour. The analysis allows to distinguish the electronic recharging process Cr(4+)(sub OCT) left & right arrow Cr(3+)(sub OCT) taking place in the octahedral sites of garnet lattice and having lower activation energy from the chromium migration process Cr(4+)(sub TETR) left & right arrow Cr(4+)(sub OCT) happening at higher temperatures or longer exposure. Estimations show that approximately 0.2% of total number of chromium ions occupied tetrahedral sites forming phototropic centers in the YAG: Mg, Cr crystal.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2001
- Accession Number
- ADP011875
Entities
People
- A. Jankowska-frydel
- A. O. Matkovskii
- B. V. Padlyak
- S. B. Ubizskii
- S. S. Melnyk
Organizations
- National University