Luminescence properties of the Eu2+ /Eu3 + activated Barium aluminate phosphors with varies Gd3+ concentration

Abstract

[EN] BaAl2O4:Eu2(+)/Eu3(+) (1mol %) co-doped with varying concentrations of Gd3(+) (1, 2, 5 and 10mol%) were prepared by combustion synthesis method at 600 degrees C. All the compositions were investigated for their structural and photoluminescence properties. Samples prepared in open atmosphere showed the presence of both Eu3(+) and Eu2(+) states which indicates the reduction of Eu3(+) to Eu2(+) during the preparation of these compounds. The prepared materials at 600 degrees C showed high intense broad peaks around 498nm corresponding to Eu2(+) and small peaks in the red region which are attributed to the presence of Eu3(+). In the 1000 degrees C annealed compounds, the intensity of the peak at 498nm got increased. The intensity of this broad band for BaAl2O4:Eu2(+)/Eu3(+)(1mol%):Gd3(+)(1mol%) was three times than that of BaAl2O4:Eu2(+)/Eu3(+)(1mol%). Thus second rare earth ion (Gd3(+)) acted as a good sensitizer and enhanced the photoluminescence intensity. The XRD spectra revealed the presence of hexagonal phase of BaAl2O4 as main phase and a small amount of a mixed phase Ba O! 6.6 Al2O3. Doping of Eu3(+), Gd3(+) did not change the crystalline structure of barium aluminate (BaAl2O4).