Ce-doped (Y yGd 1y) 3(Ga xAl 1x) 5O 12(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 Y 3Al 5O 12 structure can considerably increase the scintillation efficiency, and the spectrally corrected light yield value exceeds 44000photonMeV 1. Scintillation decay times approach that of Ce 3+ photoluminescence decay and an additional less intense slower component is also observed. Physical aspects of energy transfer process and 5d 1 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.