Effects of Postannealing on the Photoluminescence Properties of Coprecipitated Nanocrystalline BaFCl:Sm³⁺

Abstract

Nanocrystalline BaFCl:Sm(3+), as prepared by coprecipitation from aqueous solutions, is an efficient photoluminescent X-ray storage phosphor. In the present study, we report effects on its photoluminescence properties resulting from postannealing treatment in air in the temperature range between 100 to 900 °C. Interestingly, upon annealing at temperatures from 200 to 600 °C in air, a small fraction of the Sm(3+) ions in nanocrystalline BaFCl can be reduced to Sm(2+) ions. In addition to the creation of Sm(2+) ions, two different sites of Sm(3+) ions, denoted as sites A and B, are observed when the nanocrystalline BaFCl:Sm(3+) is annealed between 500 to 900 °C. The temperature dependence of photoluminescence properties of the two different sites in the 500 °C annealed sample reveals that the Sm(3+) ions at site A are possibly located at or near the crystallite surface, whereas site B is situated in a very ordered environment. To the best of our knowledge, this is the first report on the reduction of Sm(3+) ions doped in alkaline-earth fluorohalides to Sm(2+) ions by annealing in air.

Synthesis, characterization, photoluminescence and thermally stimulated luminescence investigations of orange red-emitting Sm3+-doped ZnAl2O4 phosphor

“…Recently, another group of researchers has reported two sites of Sm 3+ in BaFCl sample during annealing treatment. These authors have suggested that the first site is possibly located at or near the crystallite surface, whereas the second site is situated in a very ordered environment (Zhiqiang et al 2013). In the present work, it is believed that part of the Sm 3+ ions might have entered into the lattice replacing Al 3+ ions and the rest might be located at the surface of ZnAl 2 O 4 .…”

Structure and Photoluminescence Properties of Sm3+ Ion-Doped YInGe2O7 Phosphor

“…Sm 3+ ion is widely used as an activator of reddish orange emission due to its 4 G 5/2 → 6 H J (J = 5/2, 7/2, 9/2, 11/2) transitions, which is the most suitable source for lighting and display from a practical viewpoint [13,14,15,16]. Based on the previous information, the YInGe 2 O 7 is chosen to be the host, and references concerning the role of the rare-earth Sm 3+ ion-doped in YInGe 2 O 7 have not yet been studied.…”

Controlled Generation of Tm2+ Ions in Nanocrystalline BaFCl:Tm3+ by X-ray Irradiation

“…This is most likely due to the higher defect density in the nanocrystalline sample and microstructural arrangement of oxide impurities. A range of investigations on preparation conditions, luminescent and hole-burning properties, and the storage mechanism have been reported for this material. − These results indicate that other divalent RE ions may also be generated readily by X-irradiation in the BaFCl host lattice.…”