Difference in the Nature of Eu3+ Environment in Eu3+-Doped BaTiO3 and BaSnO3.

BaTiO3 and BaSnO3 samples doped with Eu3+ ions were prepared using glycine-nitrate gel combustion method. Relative intensities and line shapes of magnetic dipole allowed 5D0 → 7F1 and electric dipole allowed 5D0 → 7F2 transitions of Eu3+ from the hosts, BaTiO3 and BaSnO3, are significantly different. Based on detailed structural investigations, it is confirmed that synthesized BaTiO3 sample is tetragonal with no center of symmetry around Ba2+ ions. Unlike this BaSnO3 is cubic with centrosymmetric Ba2+ site. From X-ray diffraction and experimentally obtained Judd-Ofelt parameters (Ω2 and Ω4 values), it is confirmed that in BaTiO3 there is a decrease in the average Ba- O and Ba- Ba distances compared with that in BaSnO3. This leads to higher Eu- O bond polarizability and adds to the distortion in its environment around Eu3+ in BaTiO3: Eu compared with BaSnO3: Eu. This is responsible for the observed difference in the luminescence properties. [ABSTRACT FROM AUTHOR]