Optical study of Y3-xGdxAl5O12:Ce crystals grown from the melt

Y3-xGdxAl5O12:Ce (x = 0.6, 1.2, 1.8 in the melt) single crystals were grown from the melt by the Czochralski technique. XRD results shown that crystalline samples contain main garnet Y3-xGdxAl5O12 and additional Al2O3 and GdAlO3 phases. The maximal content of Gd3+ in the main garnet phase was determined at about of 40 at%. The presence of Al2O3 and GdAlO3 phases is explained by the thermal decomposition of Gd3Al5O12. The red-shift of Ce3+ emission with increasing of Gd3+ concentration in Y3-xGdxAl5O12:Ce was found. The latter is in a good agreement with data presented for Y3-xGdxAl5O12:Ce ceramics and powder phosphors.