Translucent and persistent luminescent SrAl2O4:Eu2+ Dy3+ ceramics

Ceramics that exhibit persistent luminescence are usually opaque, which limits their utility. In this work, a laser-sintering technique is employed to produce persistent luminescent SrAl2O4:Eu2+Dy3+ ceramics that has enhanced translucency in the visible spectral range. In this technique, a CO2 laser was used as the main heating source for sintering with no atmosphere control employed. The ceramics sintered at a power density of 3.1 W/mm(2) yielded homogeneous grain size distributions and transmittance up to 40% in the range of 600-800 nm. Upon sintering in air, the ceramics exhibited the characteristic green emission from the Eu2+ ion, corresponding to the 5d : 4f transition (514 nm) and a weak emission from the Eu3+ ion at 614 nm, corresponding to the D-3(0) -> 7F(2) transition. The valence of europium ions was further studied by the X-ray absorption spectroscopy in the XANES region and those details are reported herein. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.