The Ce-doped (Lu y Gd 1Àx ) 3 (Ga y ,Al 1Ày ) 5 O 12 single crystals were grown by the micropulling down method. Their structure and chemical composition were checked by X-ray diffraction (XRD) and electron probe microanalysis (EPMA) techniques. Optical, luminescent, and scintillation characteristics were measured by the methods of time-resolved luminescence spectroscopy, including the light yield and scintillation decay. Balanced Gd and Ga admixture into the Lu 3 Al 5 O 12 structure provided an excellent scintillator where the effect of shallow traps was suppressed, the spectrally corrected light yield value exceeded 40 000 photons/MeV, and scintillation decay was dominated by a 53 ns decay time value which is close to that of Ce 3+ photoluminescence decay. This study provides an excellent example of a combinatorial approach where targeted single-crystal compositions are obtained by a flexible, time saving, and cost-effective crystal growth technique.

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Ce-doped (Y y Gd1−y )3(Ga x Al1−x )5O12(x = 0, 1, 2, 3, 4 and y = 1, 2, 3) single crystals are grown by the micro-pulling down method. X-ray diffraction and electron probe microanalysis techniques are employed to check their structure and chemical composition, respectively. Optical and photoluminescence characteristics are measured and radioluminescence spectra, light yield and scintillation decay measurements are further made to evaluate the scintillation performance. We show that balanced Gd and Ga admixture in the Y3Al5O12 structure can considerably increase the scintillation efficiency, and the spectrally corrected light yield value exceeds 44 000 photon MeV−1. Scintillation decay times approach that of Ce3+ photoluminescence decay and an additional less intense slower component is also observed. Physical aspects of energy transfer process and 5d1 excited state depopulation are discussed. The micro-pulling down technique is shown as an ideal tool for a directed combinatorial search for targeted single crystal compositions to reveal those with the highest figure-of-merit for a given application field.

2inch size Ce1%:Gd 3 (Al 1-x Ga x) 5 O 12 (GAGG) single crystals with various Ga concentration of x=2, 2.4, 2.7 and 3 were grown by the Czochralski (Cz) method. Light yield has maximum value of 58000 photon/MeV at x=2.7 Ga concentration. Energy resolution was improved with decreasing Ga concentration and x=2.4 sample showed best energy resolution of 4.2%@662keV. The dependence of scintillation properties on crystal structure and AlGa was discussed.

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