(Na0.425-xLu0.575+x-yEuy)F2.15+2x (x=0, +/- 0.05, y=0.001, 0.01, 0.05) single crystals were grown from the melt by the precise atmosphere control type micro-pulling-down (mu-PD) method. The grown crystals were single-phase materials that were confirmed by X-ray diffraction, and their lattice constants increased when substitution of Lu with Eu increased. The crystals demonstrated about 90% transmittance in the 400-900 nm region that decreased with greater doping with Eu or Na. In all the crystals, strong absorption resulted from Eu2+ 5d-4f transition was observed around 200-350 nm. Eu2+ 5d-4f photoluminescence and radioluminescence under alpha-ray excitation were also detected. The crystals with low content of Eu or Na had high photoluminescence intensity; however, the radioluminescence intensity was extremely low. Intensity of the Eu3+ 4f-4f emission increased with increase in Eu concentration. Formation of Eu2+ in the grown crystals was also detected especially in those that had low content of Eu and Na. (C) 2010 Elsevier B.V. All rights reserved.