Laser sintering of persistent luminescent CaAl2O4:Eu2+Dy3+ ceramics

Described herein is the use of a laser sintering technique to produce persistent luminescence CaAl2O4:Eu2+Dy3+ ceramics exhibiting enhanced translucency in the visible/near infrared spectral range. In this technique, a CO2 laser was used as the main heating source for sintering with no atmospheric control. The ceramics sintered at a power density of 1.2 W/mm2 yielded single monoclinic CaAl2O4 phase, homogeneous grain size distributions and transmittance up to 45% in the range of 400 nm-900 nm. Upon conventional sintering in air, the ceramics exhibited the characteristic blue emission from the Eu2+ ions corresponding to the 5d → 4f transition at 440 nm, and weak emission from Eu3+ ions between 550 nm and 700 nm, corresponding to the 5D0 → 7FJ transitions.