Novel tantalum phosphate Na13Sr2Ta2(PO4)9: synthesis, crystal structure, DFT calculations and Dy3+-activated fluorescence performance

2018 ◽  
Vol 74 (9) ◽  
pp. 1045-1052 ◽  
Author(s):  
Ji Zhao ◽  
Dan Zhao ◽  
Ya-Li Xue ◽  
Qiu Zhong ◽  
Shi-Rui Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
First Principles ◽  
Three Dimensional ◽  
Photoluminescence Properties ◽  
Flux Method ◽  
Host Matrix ◽  
Open Framework ◽  
Light Excitation ◽  
Indirect Band Gap

A new tantalum phosphate, tridecasodium distrontium ditantalum nonaphosphate, Na13Sr2Ta2(PO4)9, was prepared using the high-temperature flux method. The structure can be described as a three-dimensional open framework containing isolated [TaV2(PO4)9]17−units that are interlocked by Na and Sr ions. Band structure studies by the first-principles method revealed that Na13Sr2Ta2(PO4)9is an insulator with an indirect band gap of 4.78 eV, which makes it suitable as a luminescent host matrix. A series of solid solutions,i.e.Na13Sr2–xTa2(PO4)9:xDy3+(x= 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12 and 0.14), were prepared and their photoluminescence properties studied. Under 350 nm light excitation, these emit two typical emissions of the Dy3+ion,i.e.the4F9/2→6H15/2transition centred at 476 nm and the4F9/2→6H13/2transition centred at 570 nm.

K3Eu5(PO4)6: hydrothermal synthesis, crystal structure and photoluminescence properties

2019 ◽  
Vol 75 (7) ◽  
pp. 883-890 ◽  
Author(s):  
Ya-Li Xue ◽  
Ai-Yun Zhang ◽  
Xiao-Yang Han ◽  
Xiao-Qi Cui ◽  
Ling Deng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Uv Light ◽  
Three Dimensional ◽  
Visible Region ◽  
Monoclinic Space Group ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Strong Luminescence ◽  
Light Excitation

An anhydrous orthophosphate, K3Eu5(PO4)6 (tripotassium pentaeuropium hexaphosphate), has been prepared by a high-temperature solid-state reaction combined with hydrothermal synthesis, and its crystal structure was determined by single-crystal X-ray diffraction analysis (SC-XRD). The results show that the compound crystallizes in the monoclinic space group C2/c and the structure features a three-dimensional framework of [Eu5(PO4)6]∞, with the tunnel filled by K+ ions. The IR spectrum, UV–Vis spectrum and luminescence properties of polycrystalline samples of K3Eu5(PO4)6, annealed at temperatures of 650, 700, 750, 800 and 850 °C, were investigated. Although with a full Eu3+ concentration (9.96 × 1021 ions cm−3), the self-activated phosphor K3Eu5(PO4)6 shows s strong luminescence emission intensity with a quantum yield of 37%. Under near-UV light excitation (393 nm), the series of samples shows the characteristic emissions of Eu3+ ions in the visible region from 575 to 715 nm. The sample sintered at 800 °C gives the strongest emission and its lifetime sintered at 800 °C (1.88 ms) is also the longest of all.

Synthesis, crystal structure and luminescence properties of a new samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2

2020 ◽  
Vol 76 (12) ◽  
pp. 1068-1075
Author(s):  
Dan Zhao ◽  
Lin-Ying Shi ◽  
Rui-Juan Zhang ◽  
Ya-Li Xue
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Three Dimensional ◽  
High Temperature Solution ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Temperature Solution ◽  
Light Excitation ◽  
Total Structure

A new caesium sodium samarium borate phosphate, CsNa2Sm2(BO3)(PO4)2, has been obtained successfully by the high-temperature solution growth (HTSG) method and single-crystal X-ray diffraction analysis reveals that it crystallizes in the orthorhombic space group Cmcm. The structure contains BO3, PO4, NaO7 and SmO7 polyhedra which are interconnected via corner- or edge-sharing O atoms to form a three-dimensional [Na2Sm2(BO3)(PO4)2]∞ network. This network delimits large cavities where large Cs+ cations reside to form the total structure. Under 402 nm light excitation, CsNa2Sm2(BO3)(PO4)2 exhibits three emission bands due to the 4f→4f transitions of Sm3+. Furthermore, we introduced Gd3+ into Sm3+ sites to optimize the Sm3+ concentration and improve the luminescence intensity. The optimal concentration is Gd/Sm = 98/2. The luminescent lifetime of a series of CsNa2Gd2(1–x)Sm2x (BO3)(PO4)2 phosphors shows a gradual degradation of lifetime from 2.196 to 0.872 ms for x = 0.01–0.10. The Commission Internationale de l'Eclairage (CIE) 1931 calculation reveals that CsNa2Gd1.96Sm0.04(BO3)(PO4)2 can emit orange light under 402 nm excitation.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

scholarly journals High-Pressure Synthesis, Crystal Structure, and Photoluminescence Properties of β-Y2B4O9:Eu3+

Inorganics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 136
Author(s):  
Fuchs ◽  
Schröder ◽  
Heymann ◽  
Jüstel ◽  
Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Photoluminescence Properties ◽  
Triclinic Space Group ◽  
Space Group ◽  
High Pressure High Temperature ◽  
Temperature Experiment ◽  
Pressure Synthesis

A high-pressure/high-temperature experiment at 7.5 GPa and 1673 K led to the formation of the new compound βY2B4O9. In contrast to the already known polymorph αY2B4O9, which crystallizes in the space group C2/c, the reported structure could be solved via single-crystal Xray diffraction in the triclinic space group P1 (no. 2) and is isotypic to the already known lanthanide borates βDy2B4O9 and βGd2B4O9. Furthermore, the photoluminescence of an europium doped sample of βY2B4O9:Eu3+ (8%) was investigated.

scholarly journals First-principles study of the electric, magnetic, and orbital structure in perovskite ScMnO3

RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 2143-2151 ◽  
Author(s):  
Guang Song ◽  
Yuting Chen ◽  
Guannan Li ◽  
Benling Gao
Keyword(s):  
Crystal Structure ◽  
First Principles ◽  
Three Dimensional ◽  
Orbital Structure ◽  
Orbital Ordering ◽  
First Principles Study

The crystal structure and three-dimensional alternating complementary orbital ordering of perovskite ScMnO3.

scholarly journals Crystal structure of langbeinite-related Rb0.743K0.845Co0.293Ti1.707(PO4)3

2015 ◽  
Vol 71 (3) ◽  
pp. 251-253 ◽  
Author(s):  
Nataliia Yu. Strutynska ◽  
Marina A. Bondarenko ◽  
Ivan V. Ogorodnyk ◽  
Vyacheslav N. Baumer ◽  
Nikolay S. Slobodyanik
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Point Group ◽  
Three Dimensional ◽  
Type Structure ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Point Group Symmetry ◽  
Crystallization Method ◽  
Temperature Crystallization

Potassium rubidium cobalt(II)/titanium(IV) tris(orthophosphate), Rb0.743K0.845Co0.293Ti1.707(PO4)3, has been obtained using a high-temperature crystallization method. The obtained compound has a langbeinite-type structure. The three-dimensional framework is built up from mixed-occupied (Co/TiIV)O6octahedra (point group symmetry .3.) and PO4tetrahedra. The K+and Rb+cations are statistically distributed over two distinct sites (both with site symmetry .3.) in the large cavities of the framework. They are surrounded by 12 O atoms.

Novel Red-Orange Phosphors Na2BaMg(PO4)2:Pr3+: Synthesis, Crystal Structure and Photoluminescence Performance

2018 ◽  
Vol 73 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Lu Pan ◽  
Xiaozhan Yang ◽  
Chaoyue Xiong ◽  
Dashen Deng ◽  
Chunlin Qin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Solid State Lighting ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Hexagonal Cell ◽  
X Ray ◽  
Trigonal System ◽  
Chromaticity Coordinates

AbstractA series of new red-orange emission phosphors Na2BaMg(PO4)2:Pr3+ were synthesised by a high-temperature solid-state reaction. The crystal structure and photoluminescence properties of these samples were characterised by X-ray diffraction and spectroscopic measurements. This compound holds P3̅m1 space group of the trigonal system with the lattice parameters of hexagonal cell a=0.5304(3) nm and c=0.6989(3) nm. The phosphor emits the strongest peak at 606 nm when excited by 449 nm. The average Commission Internationale de l’Eclairage chromaticity coordinates calculated for the phosphors are (0.52, 0.46). The results demonstrate the potential application of these phosphors in solid-state lighting and other fields.

scholarly journals Synthesis, crystal structure and charge-distribution validation of a new alluaudite-type phosphate, Na2.22Mn0.87In1.68(PO4)3

2020 ◽  
Vol 76 (8) ◽  
pp. 1369-1372
Author(s):  
Abdessalem Badri ◽  
Inmaculada Alvarez-Serrano ◽  
María Luisa López ◽  
Mongi Ben Amara
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Three Dimensional ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Flux Method ◽  
X Ray ◽  
Coordination Numbers ◽  
Dimensional Network ◽  
Anionic Framework

Na2.22Mn0.87In1.68(PO4)3, sodium manganese indium tris(phosphate) (2.22/0.87/1.68), was obtained in the form of single crystals by a flux method and was structurally characterized by single-crystal X-ray diffraction. The compound belongs to the alluaudite structure type (space group C2/c) with general formula X(2)X(1)M(1)M(2)2(PO4)3. The X(2) and X(1) sites are partially occupied by sodium [occupancy 0.7676 (17) and 1/2] while the M(1) and M(2) sites are fully occupied within a mixed distribution of sodium/manganese(II) and manganese(II)/indium, respectively. The three-dimensional anionic framework is built up on the basis of M(2)2O10 dimers that share opposite edges with M(1)O6 octahedra, thus forming infinite chains extending parallel to [10\overline{1}]. The linkage between these chains is ensured by PO4 tetrahedra through common vertices. The three-dimensional network thus constructed delimits two types of hexagonal channels, resulting from the catenation of M(2)2O10 dimers, M(1)O6 octahedra and PO4 tetrahedra through edge- and corner-sharing. The channels are occupied by Na+ cations with coordination numbers of seven and eight.

A novel stibium phosphate, LiBa(SbO)2(PO4)3: synthesis, crystal structure and RE3+-activated (RE = Tb3+ and Eu3+) fluorescence performance

2019 ◽  
Vol 75 (9) ◽  
pp. 1234-1242
Author(s):  
Shi-Rui Zhang ◽  
Dan Zhao ◽  
Rui-Juan Zhang ◽  
Lin-Ying Shi ◽  
Shao-Jie Dai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Red Light ◽  
Three Dimensional ◽  
Emission Spectra ◽  
Antimony Oxide ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Host Matrix ◽  
Rietveld Refinements ◽  
Light Emitting

A new stibium phosphate, lithium barium bis(antimony oxide) tris(phosphate), LiBa(SbO)2(PO4)3, was prepared by the molten salt method with LiF as the flux. The crystal structure consists of an original three-dimensional anionic framework of [(SbO)2(PO4)3]∞ built from PO4 tetrahedra sharing their corners with SbO6 octahedra. This framework delimits one-dimensional tunnels where the lithium(I) and barium(II) ions are located. The UV–Vis spectrum shows that LiBa(SbO)2(PO4)3 was transparent from 350 to 800 nm, and is thus suitable as a luminescent host matrix. We then used Tb3+ and Eu3+ activators to test its luminous performance and the purities of the prepared phosphors were studied by powder X-ray diffraction analysis with Rietveld refinements. Photoluminescence (PL) studies reveal that the emission spectra of 1 mol% RE3+-doped (RE = Tb and Eu) samples can be excited by 371 and 394 nm light, emitting green and orange–red light, respectively, for Tb3+ and Eu3+. The CIE coordinates were measured to be (0.295, 0.571) and (0.6027, 0.3967), and the luminescent lifetimes were calculated as 0.178 and 1.159 ms, respectively.

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