Vibrational spectra of sodium gadolinium tungstate NaGd(WO4)2 single crystals: Observation of spatial dispersion

Eu 3? and/or Tb 3? doped NaY(WO 4 ) 2 nanomaterials have been successfully synthesized by one-step hydrothermal method. The samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, X-ray energy dispersive spectroscopy, and photoluminescence spectra. The results show that the novel nanoplates with a diameter of 300-600 nm and the thickness of 20-25 nm are observed. Under the excitation of 246 or 230 nm, individual RE 3? ions activated NaY(WO 4 ) 2 phosphors exhibit excellent emission properties in their respective regions. The as-prepared Eu 3? or Tb 3? doped samples show strong red and green emission, originating from the allowed 5 D 0 ? 7 F J (J = 0, 1, 2) transition of the Eu 3? ions and the 5 D 4 ? 7 F J (J = 6, 5, 4, 3) transition of the Tb 3? ions. In addition, by properly tuning the relative concentration of Eu 3? ions in the case of Eu 3? and Tb 3? co-doped systems, tunable emissions in a single component are obtained under the excitation of 230 or 395 nm. Moreover, an energy transfer from Tb 3? to Eu 3? is observed, which has been justified through the luminescence spectra and the fluorescence decay curves. Furthermore, the corresponding luminescence and energy transfer mechanism have been proposed in optical transitions and possible energy transfer scheme. These results indicate that Eu 3? and Tb 3? doped NaY(WO 4 ) 2 phosphors will find potential application in the field of solid-state lighting.

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“…The two equivalent W 6? ions occupy sites of symmetry S 4 , the eight oxygen atoms are equivalent, and occupy a site of symmetry C 1 [31].…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal synthesis, multicolor tunable luminescence and energy transfer of Eu3+ or/and Tb3+ activated NaY(WO4)2 nanophosphors

Liu

Wang

et al. 2016

J Mater Sci: Mater Electron

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“…The Raman spectra further confirmed the formation of WO 4 2 À tetrahedra and its corresponding vibrations. There are four Raman bands observed in the experimental region 150-1000 cm À 1 pertaining to WO 4 2 À tetrahedral and one band related to the translational modes of metal ions [28,29]. The bands observed at 912 and 319 cm À 1 correspond to symmetric stretching and bending vibrations of WO 4 2À and the asymmetric stretching and bending vibrations were observed at 796 and 392 cm À 1 , respectively.…”

Section: Resultsmentioning

confidence: 94%

Sol–gel synthesis and photoluminescence studies on colour tuneable Dy3+/Tm3+ co-doped NaGd(WO4)2 phosphor for white light emission

Durairajan

Devakumar

Rasu

et al. 2015

Journal of Luminescence

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“…2. The bands at 3440 and 1621 cm -1 (1616 cm -1 for spectrum A) in the four spectra are from the surface water, which can be ascribed to the O-H stretching vibration and H-O-H bending vibration, respectively [15]. The bands in the range of 2850-2935 cm -1 in three FT-IR spectra (B, C and D) originate from the symmetric and asymmetric stretching vibrations of -CH 2 , indicating the absorption of the oleyl group in the samples [16].…”

Section: Methodsmentioning

confidence: 98%

Hydrothermal synthesis of NaY(WO4)2:Tb3+ powders with assistance of surfactant and luminescence properties

Sun

2015

J Mater Sci: Mater Electron

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NaY(WO 4 ) 2 :Tb 3? powders with different sizes and morphologies were synthesized by the hydrothermal process. The surfactants and reaction times have obvious effects on sizes and morphologies of samples. When there is the addition of an equimolar combination of oleic acid and oleylamine and the reaction time of 10 h, uniform morphology of octahedron can be formed. As indicated by the FTIR spectra, the enhanced adsorption of oleic acid in the presence of oleylamine leads to the good formation of octahedral NaY(WO 4 ) 2 :Tb 3? powders. Surfactants will selectively absorb on the surface of the growing particles via physical and chemical effects, which leads to different growing rates along corresponding directions and induces the formation of octahedral morphology. Under the ultraviolet excitation, NaY(WO 4 ):Tb 3? powders show dominant green emission originating from the 5 D 4 ? 7 F 5 transition of Tb 3? ions.

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Vibrational spectra of sodium gadolinium tungstate NaGd(WO4)2 single crystals: Observation of spatial dispersion

Cited by 23 publications

References 32 publications

Hydrothermal synthesis, multicolor tunable luminescence and energy transfer of Eu3+ or/and Tb3+ activated NaY(WO4)2 nanophosphors

Hydrothermal synthesis, multicolor tunable luminescence and energy transfer of Eu3+ or/and Tb3+ activated NaY(WO4)2 nanophosphors

Sol–gel synthesis and photoluminescence studies on colour tuneable Dy3+/Tm3+ co-doped NaGd(WO4)2 phosphor for white light emission

Hydrothermal synthesis of NaY(WO4)2:Tb3+ powders with assistance of surfactant and luminescence properties

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