f → f transition luminescence of Eu2+ in barium–aluminum–borate oxyfluoride glass ceramics

A new type of transparent luminescent glass ceramics with the ability to generate the line emission of Eu 2+ ions were prepared. EPR was used to explore the mechanism of transformation of the optical transition of Eu 2+ from 4f 6 5d 1 →4f 7 to 4f 7 →4f 7 .