title: Effective lattice stabilization of gadolinium aluminate garnet (GdAG) via Lu3+doping and development of highly efficient (Gd,Lu)AG:Eu3+red phosphors.
abstract: The metastable garnet lattice of Gd3Al5O12is stabilized by doping with smaller Lu3+, which then allows an effective incorporation of larger Eu3+activators. The [(Gd1-xLux)1-yEuy]3Al5O12(x= 0.1-0.5,y= 0.01-0.09) garnet solid solutions, calcined from their precursors synthesized via carbonate coprecipitation, exhibit strong luminescence at 591 nm (the5D0→7F1magnetic dipole transition of Eu3+) upon UV excitation into the charge transfer band (CTB) at ∼239 nm, with CIE chromaticity coordinates ofx= 0.620 andy= 0.380 (orange-red). The quenching concentration of Eu3+was estimated at ∼5 at.% (y= 0.05), and the quenching was attributed to exchange interactions. Partial replacement of Gd3+with Lu3+up to 50 at.% (x= 0.5) while keeping Eu3+at the optimal content of 5 at.% does not significantly alter the peak positions of the CTB and5D0→7F1emission bands but slightly weakens both bands owing to the higher electronegativity of Lu3+. The effects of processing temperature (1000-1500 °C) and Lu/Eu contents on the intensity, quantum efficiency, lifetime and asymmetry factor of luminescence were thoroughly investigated. The [(Gd0.7Lu0.3)0.95Eu0.05]3Al5O12phosphor processed at 1500 °C exhibits a high internal quantum efficiency of ∼83.2% under 239 nm excitation, which, in combination with the high theoretical density, favors its use as a new type of photoluminescent and scintillation material.
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Jinkai
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China; Advanced Materials Processing Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Ji-Guang
authors.initials: JG
authors.lastname: Li
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wu
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Shaohong
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Sun
authors.affiliation: Advanced Materials Processing Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Sakka
keywords: Eu3+ doping; gadolinium aluminate garnet; lattice stabilization; photoluminescence