Lanthanide-doped KGd3F10 nanocrystals embedded glass ceramics: Self-crystallization, optical properties and temperature sensing

Lanthanide-doped transparent bulk glass ceramics containing cubic KGd3F10 nanocrystals were successfully fabricated via self-crystallization and subsequent heat-treatment. Elemental mapping and Eu3+ optical spectroscopy evidenced the incorporation of lanthanide dopants into low-phonon-energy KGd3F10 crystalline lattice. As a consequence, bright red(green) photoluminescence was achieved for the Ce/Eu(Tb) co-doped glass ceramics via energy transfer of Ce3+-> Gd3+ -> Eu3+(Tb3+), and intense tunable upconversion emissions were realized for the Yb/Ln (Ln = Er, Ho, Tm) co-doped glass ceramics via a multi-photon absorption process. Furthermore, temperature-dependent optical performance of Yb/Er and Yb/Tm co-doped glass ceramics was systematically studied to explore their possible application as optical thermometric media. Impressively, fluorescence intensity ratios of Er3+ H-2(11/2)/S-4(3/2) thermally coupled states as well as Tm3+ F-3(2,3)/(1)G(4) non-thermally coupled ones were evidenced to be applicable as temperature probes. (C) 2018 Elsevier B.V. All rights reserved.