THE LUMINESCENCE AND STRUCTURE OF NOVEL TRANSPARENT OXYFLUORIDE GLASS-CERAMICS

New transparent oxyfluoride glass-ceramics can provide a low phonon en ergy fluoride environment for active rare earth ions while maintaining the formability and physical properties of an oxide glass. Transparen t glass-ceramics were made by casting crucible melted glass onto a ste el plate and subsequently heating the resultant glass patty above the glass transition temperature to nucleate and grow LaF3 crystals. Eu3doped glasses emit only red luminescence from the D-5(0) level but aft er heat treatment emit blue, green, and red luminescence indicative of a low phonon energy rare earth environment. TEM micrographs and XRD s how no features in the base glass, but do show extensive LaF3 crystall ites after heat treatment that are responsible for the novel optical p roperties of these hybrid materials. (C) 1998 Elsevier Science B.V. Al l rights reserved.