Influence of Substitution of LiNbO3 in Enhancing Luminescence in Eu3+ Activated Strontium Titanate

Photoluminescence and the change of local crystal structure of perovskite solid solution compounds (SrTiO3)(x)(LiNbO3)(1-x): Eu3+ were investigated by altering the concentration of LiNbO3. Red emission intensity enhanced by 6.5 times along with the increase of asymmetric ratio by 1.6 times on increasing the concentration of LiNbO3 from 0 to 25 mol%. X-ray diffraction analysis confirmed the expansion of unit cell due to the incorporation of LiNbO3. The enhancement of intensity of the first order Raman vibrations at 550 cm(-1) (TO4) and bending vibrations of Nb-O-Nb linkage at 268 cm(-1) (A(1)(TO1)) evidences the increase of dopant concentration. The change in local co-ordination, charge compensation effect, and the low phonon nature of LiNbO3 attributed the enhancement observed in luminescence properties