Elaboration of blue-emitting blue pigments based on Eu2+/Co2+ codoped BaMgAl10O17 through the heterogeneous distribution of dopants

Photoluminescence and coloring properties of Eu2+/Co2+ codoped BaMgAl10O17 were investigated to produce inorganic blue-luminescent pigments. Two kinds of synthesis methods were employed for BaMgAl10O17:Eu2+,Co2+ powders based on a conventional solid-state reaction and a newly developed precipitation method. Powder samples through the solid-state reaction exhibited blue photoluminescence from Eu2+, which was quenched considerably by codoping with Co2+ due to the occurrence of a Eu2+ → Co2+ energy transfer. The precipitation method was then conceived to separate Eu2+ and Co2+ spatially in a BaMgAl10O17 particle. Powder samples through the precipitation method could be colored blue by optical absorption of Co2+ without degrading blue photoluminescence from Eu2+. The inhomogeneous distribution of the Eu2+/Co2+ dopants in the BaMgAl10O17 particles was instrumental to the suppression of the Eu2+ → Co2+ energy transfer.

► Blue-luminescent pigments were produced in a Eu2+/Co2+ codoped BaMgAl10O17 system. ► We employed both a solid-state reaction and a newly developed precipitation method. ► Homogeneous distribution of the Eu2+/Co2+ dopants resulted in luminescence quenching. ► Inhomogeneous distribution of the dopants led to blue coloring and blue luminescence.