Color and Luminescence Centers in LuAG and Pr:LuAG Crystals Before and After {sup 60}Co γ-Irradiation

Journal Article · Sun Jul 15 00:00:00 EDT 2018 · Optics and Spectroscopy

DOI:https://doi.org/10.1134/S0030400X18070147· OSTI ID:22786341

Khaiitov, I. A. ^[1]; Vil’danov, R. R. ^[2]; Amonov, M. Z. ^[1]

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1. Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan)
2. National University of Uzbekistan (Uzbekistan)

The absorption and thermoluminescence spectra and their relaxation in pure and praseodymium-doped LuAG crystals are comparatively studied to determine the contribution of intrinsic and impurity defects before and after irradiation by {sup 60}Co γ-quanta with an average energy of 1.25 MeV, dose rate of 0.8 Gy/s, and dose of 10{sup 3} Gy at 310 K. The existence of intrinsic F{sup +} defects with a typical absorption band at 375 nm and impurity Cr{sup 4+} centers absorbing at 285, 420, 490, and 595 nm in both LuAG and Pr:LuAG samples before irradiation is related to the crystal-growth technology and the impurity composition of the charge. An increase in the concentration of F{sup +} and Cr{sup 4+} centers after γ-irradiation is caused by charging of neutral F centers and changing of the electronic state (valence) of Cr{sup 3+} impurity centers. Formation of antisite defect complexes Lu{sub Al}{sup 3+}–V{sub O}, which are responsible for a luminescence band at 335 nm, is suggested. The first broad peak at 340 K on the thermoluminescence curves of both samples after irradiation with a dose of 10{sup 3} Gy is related to liberation of charge carriers from shallow trapping levels; thermal activation and radiative recombination with emitting centers begin at 310 K, which places the upper limit on the temperature range of application of these scintillation crystals.

• OSTI ID: 22786341
• Journal Information: Optics and Spectroscopy, Vol. 125, Issue 1; Other Information: Copyright (c) 2018 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0030-400X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
CHARGE CARRIERS
COBALT 60
COLOR
CONCENTRATION RATIO
CRYSTALS
DEFECTS
DOPED MATERIALS
DOSE RATES
F CENTERS
GAMMA RADIATION
IMPURITIES
MEV RANGE 01-10
PHYSICAL RADIATION EFFECTS
PRASEODYMIUM ADDITIONS
RECOMBINATION
RELAXATION
SCINTILLATIONS
SPECTRA
THERMOLUMINESCENCE