Variation of emission color of Y3Al5O12:Ce induced by thermal treatment at reducing atmosphere

Abstract Nanocrystalline powders of Y 3 Al 5 O 12 :Ce (YAG:Ce) were prepared using Pechini technique and precipitation with urea at 80–90 °C. It was shown that material obtained using Pechini procedure, after heating at 900–1000 °C is crystallographically pure, while that made with urea is contaminated with Y 4 Al 2 O 9 and YAlO 3 . For all powders, heating at reducing atmosphere of nitrogen–hydrogen mixture at 1000 °C caused a red shift of the Ce 3+ luminescence by about 20–25 nm. The effect was stronger for the powder prepared with urea. Also this powder was characterized by a longer decay time of the Ce 3+ emission indicating the treatment at reducing atmosphere diminished nonradiative relaxation probability of the excited electrons.