Intrinsic trapping sites in rare-earth and yttrium oxyorthosilicates

Similarity among the thermally stimulated luminescence glow curves of undop ed Lu2SiO5 and Ce3+-doped oxyorthosilicates possessing the monoclinic C2/c structure strongly suggests the luminescence traps are intrinsic in origin. They are most likely associated with the configuration of oxygen ions in t he vicinity of not only the Ce3+ ion, as suggested in previous work, but al so the host lanthanide ion. The optical absorption spectrum of pristine Lu2 SiO5 shows the presence of intrinsic absorption centers that are enhanced u pon x irradiation as seen in other oxides containing oxygen related point d efects. (C) 1999 American Institute of Physics. [S0021-8979(99)06921-2].