Room-temperature scintillation properties of cerium-doped REOX (RE=Y, La, Gd, and Lu; X=F, Cl, Br, and I)

Abstract

The scintillation properties of cerium-doped oxyhalides following the general formula REOX (RE=Y, La, Gd, and Lu; X=F, Cl, Br, and I) are reported. These materials were synthesized under dry conditions as microcrystalline powders from conventional solid state reactions. The room temperature X-ray excited emission and scintillation decay curves were measured and analyzed for each material. Additionally, the hygroscopic nature of the oxychlorides and oxybromides was compared to that of their corresponding rare earth halides. The yttrium, lanthanum, and gadolinium oxychlorides, and all of the oxybromides and oxyiodides are found to be activated by Ce 3+ . GdOBr doped with 0.5% Ce 3+ has the highest light output with a relative luminosity of about one-half that of LaBr 3 : Ce 3+ . It displays a single exponential decay of 30 ns. Research Highlights►Room temperature scintillation properties of cerium doped rare earth oxyhalides. ►Oxybromides and oxyiodides most efficient scintillators. ►Cerium activation may be linked to structure.

Ba11La4Br34: a new barium lanthanum bromide

“…For a detailed study of the luminescence properties of the title compound, see : Eagleman et al (2011). Similar structure types to that of the title compound have been observed in ternary alkaline earth and rare earth fluorides (Bevan et al, 1980(Bevan et al, , 1982Burns et al, 1968), chlorides (Liu & Eick, 1988Lö chner & Blachnik, 2011;Meyer & Masselmann, 1998), and bromides (Masselmann & Meyer, 1999;Liu & Eick, 1989) and in mixed valent rare earth halides (Druding & Corbett 1961;Liu & Eick, 1991).…”

“…For structural details of these types of superstructures, see : Meyer & Masselmann (1998 displays high luminosities making them attractive as a promising scintillators. A detailed study of the luminescence properties will be presented in a future publication (Eagleman et al 2011).…”

Significantly different pulse shapes for γ- and α-rays in Gd3Al2Ga3O12:Ce3+ scintillating crystals

“…Physical and scintillation properties, which include the wavelengths l em (or l ex ) of the emission (excitation) peak, the light yield (LY) per unit energy loss, and the decay constants t , are compared for Gd 3 Al 2 Ga 3 O 12 (GAGG), Gd 2 SiO 5 , GdAlO 3 , GdBr 3 , and RbGd 2 Br 7 , all of which are doped with Ce 3 þ . Besides these crystals, GdOBr:Ce 3 þ [13,14] is also known as a dense and efficient scintillator with the density¼6.82 g/cm 3 , radiation length X 0 ¼1.30 cm, l em ¼405, 440 nm, l ex ¼370 nm, LY¼ 30,000 ph/MeV, and t¼30 ns. This material, however, is not grown in large bulk crystals but only in thin wafers, due to the significant cleavage along the (0 0 1) plane.…”

A feasible strategy to synthesize LaOI:Yb3+/Ho3+ upconversion luminescence nanostructures via succeeding to the morphologies of precursors

“…Meanwhile, La 3+ ion has the largest ionic radius among the lanthanide ions, and it can be easily substituted by different Ln 3+ ions in the structure [35]. So far, LaOI bulk powders have been prepared via direct solid-state reaction at high temperature [36,37] composites under argon atmosphere. The morphology, structure, and UC photoluminescence properties of the resulting samples were investigated in detail.…”

“…Youmo Li prepared LaOI bulk powders as follows: La 2 O 3 and NH 4 I were mixed and reacted under argon flow at 1000°C for 10 h, or KI and KNO 3 were added into the starting mixture as cosolvent[36]. Eagleman et al also prepared LaOI powders using the following method: La 2 O 3 and LaI 3 powders were mixed in capped alumina tubes, and reacted under 3%H 2 /argon flow at 1000°C for 10 h, and thus LaOI were synthesized[37]. Nevertheless, LaOI:Yb 3+ /Ho 3+ one-dimensional (1D) nanostructures cannot be easily prepared using the above process via electrospinning technique.…”