The analyses of structure and luminescence in (MgyY3-y) (Al5-ySiy)O12 and Y3(MgxAl5-2xSix)O12 ceramic phosphors

In this paper, the chemical composition of Y3Al5O12 was modified to Ce:(MgyY2.99-y) (Al5-ySiy)O-12 (MYASG) and Ce:Y-2.99(MgxAl5-2xSix)O-12 (YMASG) through the Mg2+-Si4+ substitution for Y3+-Al3+ and Al3+-Al3+, respectively. The increasing (decreasing) lattice constants, downward (upward) shift of Raman peaks and shorter (longer) luminescence lifetime were investigated in YMASG (MYASG) through the Rietveld analysis, Raman spectra and luminescent decay spectra. Moreover, a massive red-shift emission peak was observed in YMASG, from 537 nm to 577 nm. While for MYASG, the maximum emission peak of Ce3+ locates at 552 nm and the emission peaks remain unchanged even further increasing Mg2+-Si4+. The distinct red-shift properties can be ascribed to the different crystal structure due to the Mg2+ doping in different coordinate sites and are clarified by the configuration coordinate model. The broad color area from yellow to orange region in the color coordinates diagram was achieved which proves the great potential application of YMASG ceramic phosphors in the warm white light illumination. (C) 2019 Elsevier B.V. All rights reserved.