BLUE-LIGHT EMISSION FROM NANOCRYSTALLINE LA0.5NA0.5TIO3

Nanocrystalline La0.5Na0.5 TiO3 powders were prepared by the stearic a cid-gel method, and the grain sizes could be controlled by varying ann ealing temperatures. The sizes were determined to be from 14 to 50 nm using Scherrer's formula. A very strong blue-light emission band aroun d 480 nm was clearly observed in the nano-sized La0.5Na0.5TiO3 with a grain size of 14 nm at room temperature. Also, nano-size effects on th e luminescence properties were investigated, These results could be ex plained with the aid of a self-trapped exciton model.