Synthesis of Li–Ta–Ti–O new red phosphors with Mn4+ as activator and the relationship between photoluminescence intensity and crystal structure

摘要

In the Lisub2/subO–Tasub2/subOsub5/sub–TiOsub2/sub system, Lisub1+/sub subx/sub sub?/sub suby/sub Tasub1?/sub subx/sub sub?3/sub suby/sub Ti subx/sub sub+4/sub suby/sub Osub3/sub (0.14 ≤ x ≤ 0.175, 0.04 ≤ y ≤ 0.175) forms a superstructure by periodical insertion of an intergrowth layer in a matrix having a trigonal structure. In this study, to apply this unique structure as a host material of phosphor, new phosphors with a red emission color were synthesized by doping Mnsup4+/sup ion. The phosphor emitted at around 685 nm excited by 493 nm. The photoluminescence (PL) intensity closely related to the ratio of Mnsup4+/sup/Mnsup3+/sup ion because the ratio changed by sintering temperature and/or Ti content in the matrix. The relationship between PL intensity and crystal structure was investigated using X-ray diffraction, a transmission electron microscope, and X-ray absorption fine structure.