Microstructure and luminescence of rare earth doped Li(Nb,Ti)O₃ solid solutions

Li_1+x−yNb_1−x−3yTi_x+4yO₃ (0.11≤x≤0.33, 0≤y≤0.09) solid solutions in the Li₂O-Nb₂O₅-TiO₂ ternary system are known as M Phase with superstructure. Eu doped Li_1+x−yNb_1−x−3yTi_x+4yO₃ (LNT) solid solutions were prepared by firing mixed powders at temperatures of 1120 °C for up to 24 hours. The interval of intergrowth layers of Eu doped LNT solid solution was as twice as that of no doped LNT solid solution. Another rare earth (Dy, Sm, Tm, Er) doped LNT solid solutions were also prepared each other. These LNT solid solutions with 20 mol%-TiO₂ did possess a disorder structure, but did not possess a superstructure. PL intensity of Eu doped LNT solid solution was higher than Eu doped LiNbO₃ (LN) solid solution. However, PL intensity of another rare earth doped LNT solid solutions was less than LN solid solutions each other. It was thought that the distribution of Eu and Ti and a relative distance between Eu and Ti were optimized by the formation of the superstructure and PL intensity of Eu doped LNT solid solutions increased.