ИСТИНА

Here, we present the results of our study of the optical and photoluminescence properties of GAGG:Ce crystals irradiated by electron beam. All investigated samples were cut from crystals grown in JSC “Fomos-Materials” Co. using Czochralski method in Ir crucibles. The studies were performed on as-grown samples and on samples annealed in oxygen and vacuum. Electron irradiation was performed at the Center of Physical Measurements Investigations of IPCE RAS using the linear accelerator (energy 4.5 MeV, flux 4·1012 cm–2·s–1, fluence 1.2∙1016 cm-2). Optical properties of samples were studied using UV-Vis-NIR spectrophotometer “Cary-5000” (Agilent Technologies) at non-polarized light. Luminescent properties were studied using specialized set-up. A 150 W xenon lamp was used as an excitation source. The sample was placed into vacuum optical cryostat Cryotrade LN-120. The luminescence was registered using LOT-Oriel MS-257 spectrometer equipped with CCD detector. It was shown that post growth annealing in vacuum has insignificant effect on GAGG:Ce optical properties. Annealing in oxygen leads to increase of absorption in near UV and visible wavelength regions. The defect structure has been also studied using luminescence spectroscopy, that allowed to obtain deeper insight to their origin. Electron irradiation did not result in significant changes of optical properties of GAGG:Ce. Therefore, obtained results show high rate of radiation hardness of GAGG:Ce crystals.