SrAl2O4:Eu2+(, Dy3+) Nanosized Particles: Synthesis and Interpretation of Temperature-Dependent Optical Properties. (23rd February 2015)

• Record Type: Journal Article
• Authors: Terraschke, Huayna; Suta, Markus; Adlung, Matthias; Mammadova, Samira; Musayeva, Nahida; Jabbarov, Rasim; Nazarov, Mihail; Wickleder, Claudia
• Other Names: Oura Masaki Academic Editor.
• Is Part Of: Journal of spectroscopy. Volume 2015(2015)
• Publication Date: 2015-02-23
• Subjects: Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1155/2015/541958
• Languages: English
• ISSNs: 2314-4920

Abstract

Abstract : SrAl2 O4 nanosized particles (NPs) undoped as well as doped with Eu 2+ and Dy 3+ were prepared by combustion synthesis for the discussion of their intensively debated spectroscopic properties. Emission spectra of SrAl2 O4 :Eu 2+ (, Dy 3+ ) NPs are composed by a green band at 19 230 cm −1 (520 nm) at room temperature, assigned to anomalous luminescence originated by Eu 2+ in this host lattice. At low temperatures, a blue emission band at 22 520 cm −1 (444 nm) is observed. Contrary to most of the interpretations provided in the literature, we assign this blue emission band very reliably to a normal 4f 6 ( 7 F J )5d(t2g )→4f 7 ( 8 S7/2 ) transition of Eu 2+ substituting the Sr 2+ sites. This can be justified by the presence of a fine structure in the excitation spectra due to the different 7 F J levels (J = 0 ⋯ 6 ) of the 4f 6 core. Moreover, Fano antiresonances with the 6 I J (J = 9 / 2, 7 / 2 ) levels could be observed. In addition, the Stokes shifts (Δ E S = 1 980 cm −1 and 5 270 cm −1 for the blue and green emission, resp.), the Huang-Rhys parameters of S = 2.5 and 6, and the average phonon energies of ħ ω = 480 cm - 1 and 470 cm −1 coupled with the electronic states could be reliably determined.