Effect of Electron Irradiation on the Optical Properties of Gadolinium-Aluminum-Gallium Garnet Crystals

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques Vol. 15; no. 6; pp. 1259 - 1263
• Main Authors: Kasimova, V. M., Kozlova, N. S., Buzanov, O. A., Zabelina, E. V., Lagov, P. B., Pavlov, Yu. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2021; Springer Nature B.V
• Subjects: Absorption spectra; Aluminum; Cerium; Chemistry and Materials Science; Color centers; Crystal defects; Crystal lattices; Crystals; Doped crystals; Electron irradiation; Electron transitions; Gadolinium; Gallium; Garnets; Materials Science; Optical properties; Refractivity; Surfaces and Interfaces; Thin Films; cerium doping; electron irradiation; substitutions in the cation sublattice; scintillator; color centers; transmission specrum; refractive index
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S1027451021060318

The effect of electron irradiation on the properties of crystals of gadolinium-aluminum-gallium garnets Gd 3 Al 2 Ga 3 O 12 (Al : Ga = 2 : 3), Gd 3 Al 3 Ga 2 O 12 (Al : Ga = 3 : 2) and crystals doped with cerium Gd 3 Al 2 Ga 3 O 12 :Ce (Al : Ga = 2 : 3) (GAGG:Ce) is studied. The irradiation of cerium-doped crystals with electron doses from 300 to 2500 Mrad does not affect the optical properties of the crystals, which indicates their resistance to the formation of defects under high-energy irradiation. The optical transmission spectra of undoped Gd 3 Al 2 Ga 3 O 12 and Gd 3 Al 3 Ga 2 O 12 crystals noticeably decreases after irradiation with electron doses of 300 and 400 Mrad and these initially colorless crystals become brownish. A broad absorption band appears in the wavelength range of 350–500 nm, which is associated with the formation of structural defects such as color centers. The refractive indices of the crystals Gd 3 Al 2 Ga 3 O 12 and GAGG:Ce barely change, but Gd 3 Al 3 Ga 2 O 12 shows an increase in n (λ) depending on the exposure to high-energy radiation. The characteristic absorption bands of unirradiated GAGG:Ce with maxima at 340 and 440 nm are likely associated with the formation of crystal-lattice defects, and not only with electronic transitions of Ce.