Laser sintering and optical characterization of SrAl2-xBxO4:Eu,Dy ceramics

In this work, we describe the influence of the Eu and Dy concentrations on the persistent luminescent properties of Sr(1-x-y)B0.06Al1.94O4:Eux,Dyy (SABED) ceramics sintered by a new laser sintering technique. In this procedure, a CO2 laser is employed as the heating source for sintering. The ceramics yielded a single monoclinic structure, homogeneous grain size, and a diffuse transmittance of 60 % in the range of 400 to 800 nm. The samples also exhibited an intense emission band centered at 512 nm, characteristic of the Eu2+ 5d-4f transition, and remained visible to the naked eye for 10 min, despite having been sintered in open atmosphere. The Eu valence state was investigated via X-ray absorption near-edge (XANES) at the Eu LIII-edge (6977 eV) and evidenced that the Eu2+/Eu3+ ratio increases as the dopant concentration decreases. Therefore, this study presents an alternative method to produce high translucent and persistent luminescent ceramics without control of the atmosphere.