Photoluminescence characterization of Ca10Na(PO4)7:Eu3+ red-emitting phosphor

Bond energy, site preferential occupancy and Eu2+/3+ co-doping system induced by Eu3+ self-reduction in Ca10M(PO4)7 (M = Li, Na, K) crystals

Ca₁₀M(PO₄)₇:Eu (M = Li, Na, K) phosphors have been synthesized via a solid-state reaction process, their phase purity was examined using XRD patterns, and Rietveld refinement confirmed that the Ca₁₀Li(PO₄)₇, Ca₁₀Na(PO₄)₇ and Ca₁₀K(PO₄)₇ are pure phases.

Dy3+ -, Sm3+ -, Ce3+ - and Tb3+ -activated optical properties of microcrystalline BaMgP2 O7 phosphors

Photoluminescence (PL) and thermoluminescence (TL) properties of rare earth (RE) ion (RE = Dy³⁺ , Sm³⁺ , Ce³⁺ , Tb³⁺ ) activated microcrystalline BaMgP₂ O₇ phosphors are presented in this work. Non-doped and doped samples of BaMgP₂ O₇ were prepared using a solid state diffusion method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), PL and TL. The XRD measurement confirmed the phase purity of the BaMgP₂ O₇ host matrix. The average particle size was found through SEM measurement to be around 2 μm. All activators using the PL technique displayed characteristic excitation and emission spectra that corresponded to their typical f → f and f → d transitions respectively. Thermoluminescence measurements showed that BaMgP₂ O₇ :RE (RE = Dy³⁺ , Sm³⁺ , Tb³⁺ , Ce³⁺ ) and co-doped BaMgP₂ O₇ :Ce³⁺ ,Tb³⁺ phosphors have also TL behaviour.

The effect of vanadium substitution on photoluminescent properties of KSrLa(PO4)x(VO4)2−x:Eu3+ phosphors, a new variant of phosphovanadates

In the KSrLa_1−y(PO₄)_x(VO₄)_2−x:yEu³⁺ system, luminescence properties of Eu³⁺ can be enhanced via substitution of phosphate with vanadate.

Synthesis and luminescence of Eu(3+)-doped in triple phosphate Ca8MgBi(PO4)7 with whitlockite structure

Triple whitlockite-type structure-based red phosphors Ca8 MgBi1-x(PO4)7:xEu(3+) (x = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80 and 1.00) were synthesized by a conventional solid-state reaction route and characterized by their X-ray crystal structures. The X-ray diffraction (XRD) patterns, Fourier transform infrared spectra, morphologies, photoluminescence spectra, UV/Vis reflectance spectra, decay times and the International Commission on Illumination (CIE) chromaticity coordinates of Ca8MgBi1-x(PO4)7:xEu(3+) were analyzed. Eu-doped Ca8MgBi(PO4)7 phosphors exhibited strong red luminescence with peaks at 616 nm due to the (5)D0 → (7)F2 electric dipole transition of Eu(3+) ions after excitation at 396 nm. The UV/Vis spectra indicated that the band gap of Ca8MgBi0.30(PO4)7:0.70Eu(3+) is larger than that of Ca8MgBi(PO4)7. The phosphor developed in this study has great potential as a red-light-emitting phosphor for UV light-emitting diodes.

Rietveld refinement of AgCa10(PO4)7 from X-ray powder data

Polycrystalline silver(I) deca-calcium heptakis(orthophos-phate), AgCa10(PO4)7, was obtained by solid-state reaction. It is isotopic with members of the series MCa10(PO4)7 (M = Li, Na, K and Cs), and is closely related to the structure of β-Ca3(PO4)2. The crystal structure of the title compound is built up from a framework of [CaO9] and two [CaO8] polyhedra, one [CaO6] octa-hedron (site symmetry 3.) and three PO4 tetra-hedra (one with site symmetry 3.). The Ag(+) cation is likewise located on a threefold rotation axis and resides in the cavities of the rigid [Ca10(PO4)7](-) framework. It is surrounded by three O atoms in an almost regular triangular environment.