Evidence of Optically Stimulated Luminescence in Lu₃Al₅O₁₂:Ce

Abstract

Lutetium aluminum garnet, commonly known as LuAG, is a versatile material finding numerous optical applications, and whose scintillation properties have been widely investigated. In this study, experimental evidences of optically stimulated luminescence (OSL) phenomena occurring in LuAG:Ce crystals are shown. After demonstrating the possibility to optically bleach an electron trap responsible for a thermally stimulated luminescence (TSL) peak at 280 C (heating rate 1.7 C s À1 ) using red light, a direct measurement of the OSL decay curve and of the resulting characteristic Ce 3þ 5d-4f emission spectrum is carried out. The assessment of the bleaching spectrum of the TSL peak at 280 C reveals that light with wavelength in the 600-650 nm interval is the most efficient in depleting the TSL peak, making He-Ne lasers suitable sources of optical stimulation. The finding of OSL features in LuAG: Ce paves the way to new application perspectives. In particular, the achievement of a good balance between scintillation and energy storage properties of LuAG.Ce can drive a constructive integration between X-rays imaging approaches based on photo-stimulable phosphors and those exploiting scintillating materials.

Basic Characteristics of Dose Distributions of Photons Beam for Radiotherapeutic Applications Using YAG:Ce Crystal Detectors

“…Apart from the scintillation applications, YAG:Ce and LuAG:Ce crystals with ρ = 4.5 g/cm 3 ; Z eff = 35 and ρ = 6.75 g/cm 3 ; Z eff = 59, respectively, recently emerged as possible alternative materials for TL dosimetry due to high TSL signal and good position of main glow peak in the 250–300 K range after irradiation of different types of ionization radiation [ 7 , 12 , 13 ]. Moreover, the TSL and OSL properties of YAG:Ce and LuAG:Ce crystals were considered in detail [ 7 , 9 , 12 , 14 , 15 ]. Due to such properties, YAG:Ce and LuAG:Ce crystals can be a good candidates for radiative and chemical resistant detectors with small volume and high spatial resolution [ 16 ].…”

Infrared Stimulated Luminescence of Ce3+ Doped YAG Crystals

“…Recently, it was found that scintillating materials of the garnet family may also exhibit interesting properties of optically stimulated luminescence (OSL), which potentially may be exploited for ionizing radiation dosimetry. Firstly, a red-stimulated luminescence was found in lutetium-aluminum garnet [ 8 ], and then, in our previous paper, we described infrared-stimulated luminescence of gadolinium aluminum-gallium mixed garnet Gd 3 Ga x Al 5−x O 12 (GGAG:Ce) [ 9 ]. When stimulated with IR at about 870 nm, the previously irradiated GGAG:Ce crystals exhibit very strong luminescent emission in the range of 500–600 nm, which is typical for Ce 3+ emission in garnets.…”

“…In general, some of these clustering centers may have excitation (absorption) spectra in the IR range. Taking into account that the intensity of IR OSL usually depends on the dopant concentration [ 8 , 9 ], the formation of pair centers with the participation of YAG host defects and Ce 3+ ions was not excluded as well. Identification of the nature of such centers is a hot topic and such research with the use of theoretical calculation [ 15 , 16 ], advanced optical methods [ 19 , 20 ], and radio-spectroscopic investigations [ 25 ] is performed on various garnet compounds.…”