Optical and electron paramagnetic resonance studies of Fe impurities in yttrium aluminum garnet crystals

Journal Article · Tue Nov 01 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.8555· OSTI ID:6749516

Chen, C Y; Pogatshnik, G J; Chen, Y; Kokta, M R

Optical-absorption and electron paramagnetic resonance (EPR) techniques were used to study iron impurities in yttrium aluminum garnet (YAG) crystals. Due to its low symmetry, YAG containing Fe/sup 3+/ exhibited many EPR lines. Fe/sup 3+/ ions in octahedral and tetrahedral sites were identified. A correlation study involving both EPR and optical-absorption measurements indicated that the absorption band at 255 nm, which had been previously attributed to an Fe/sup 3+/ charge-transfer band, was a composite charge-transfer band made up of contributions from substitutional Fe/sup 3+/ at both symmetry sites. Oxidation and reduction experiments up to 1700 K were performed. The former increased the Fe/sup 3+/ concentration, and the latter diminished it. Conversion of Fe/sup 2+/ to Fe/sup 3+/ was governed by a thermal activation energy of 3.0 +- 0.3 eV.

• Research Organization: Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• OSTI ID: 6749516
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:13; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ABSORPTION SPECTROSCOPY
ALLOYS
CRYSTAL DOPING
CRYSTAL STRUCTURE
ELECTRON SPIN RESONANCE
FERRITE GARNETS
HEAT TREATMENTS
IMPURITIES
IRON ADDITIONS
IRON ALLOYS
MAGNETIC RESONANCE
MINERALS
RESONANCE
SILICATE MINERALS
SPECTROSCOPY
VERY HIGH TEMPERATURE