Luminescence Properties of Eu2+/Eu3+Activated Barium Aluminate Phosphors with Gd3+Concentration Variation
Transactions of the Indian Ceramic Society
BaAl 2 O 4 :Eu 2+ /Eu 3+ (1 mol %) co-doped with varying concentrations of Gd 3+ (1, 2, 5 and 10 mol%) were prepared by combustion synthesis method at 600 o C. All the compositions were investigated for their structural and photoluminescence properties. Samples prepared in open atmosphere showed the presence of both Eu 3+ and Eu 2+ states which indicates the reduction of Eu 3+ to Eu 2+ during the preparation of these compounds. The prepared materials at 600 o C showed high intense broad peaks
... tense broad peaks around 498 nm corresponding to Eu 2+ and small peaks in the red region which are attributed to the presence of Eu 3+ . In the 1000 o C annealed compounds, the intensity of the peak at 498 nm got increased. The intensity of this broad band for BaAl 2 O 4 :Eu 2+ /Eu 3+ (1 mol%):Gd 3+ (1 mol%) was three times than that of BaAl 2 O 4 :Eu 2+ /Eu 3+ (1 mol%). Thus second rare earth ion (Gd 3+ ) acted as a good sensitizer and enhanced the photoluminescence intensity. The XRD spectra revealed the presence of hexagonal phase of BaAl 2 O 4 as main phase and a small amount of a mixed phase Ba O! 6.6 Al 2 O 3 . Doping of Eu 3+ , Gd 3+ did not change the crystalline structure of barium aluminate (BaAl 2 O 4 ).