Synthesis and structural characterization of ASnFe(PO4)3 (A=Na2,Ca,Cd) phosphates with the Nasicon type structure

The crystal structures of ASnFe(PO4)3 (A=Na2, Ca, Cd) phases, obtained by conventional solid state reaction techniques at (950–1000 °C), were determined at room temperature from X-ray powder diffraction (XRD) using Rietveld analysis. The three materials exhibit the Nasicon-type structure (R3c space group, Z=6) with a random distribution of Sn(Fe) within the framework. Hexagonal cell parameters when A=Na2, Ca and Cd are: a=8.628(1) Å, c=22.151(2) Å; a=8.569(1) Å, c=22.037(2) Å and a=8.587(1) Å, c=21.653(2) Å, respectively. Structural refinements show a partial occupancy of M1 (Na(1)) and M2 (Na(2)) sites in Na2SnFe(PO4)3 leading to the cationic distribution [Na1.22□1.78]M2[Na0.78□0.22]M1SnFe(PO4)3. Ca2+ ions are distributed only in the M1 site of [□3]M2[Ca]M1SnFe(PO4)3. From XRD data, it is difficult to unambiguously distinguish between Cd2+ and Sn4+ ions in CdSnFe(PO4)3. Nevertheless the overall set of cation–anion distances within the Nasicon framework clearly shows that the cationic distribution can be illustrated by the [□3]M2[Cd]M1SnFe(PO4)3 crystallographic formula. Distortion within the [Sn(Fe)(PO4)3] frameworks, in ASnFe(PO4)3 (A=Na2,Ca,Cd) phases, is shown to be related to the M1 site size. © 2004 International Centre for Diffraction Data.

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Structural characterization of two K2SnX(PO4)3 (X=Fe,Yb) with langbeinite structure

Powder Diffraction ◽

10.1154/1.2246229 ◽

2006 ◽

Vol 21 (3) ◽

pp. 214-219 ◽

Cited By ~ 7

Author(s):

Abderrahim Aatiq ◽

Btissame Haggouch ◽

Rachid Bakri ◽

Youssef Lakhdar ◽

Ismael Saadoune

Keyword(s):

Solid State ◽

Powder Diffraction ◽

Room Temperature ◽

Cell Parameter ◽

Rietveld Analysis ◽

Conventional Solid State Reaction ◽

X Ray ◽

Octahedral Sites ◽

Parameter Values

Structures of two K2SnX(PO4)3(X=Fe,Yb) phosphates, obtained by conventional solid state reaction techniques at 950 °C, were determined at room temperature by X-ray powder diffraction using Rietveld analysis. The two materials exhibit the langbeinite-type structure (P213 space group, Z=4). Cubic unit cell parameter values are: a=9.9217(4) Å and a=10.1583(4) Å for K2SnFe(PO4)3 and K2SnYb(PO4)3, respectively. Structural refinements show that the two crystallographically independent octahedral sites (of symmetry 3) have a mixed Sn∕X (X=Fe,Yb) population although ordering is stronger in the Yb phase than in the Fe phase.

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Crystallochemistry and structural studies of two newly CaSb0.50Fe1.50(PO4)3 and Ca0.50SbFe(PO4)3 Nasicon phases

Powder Diffraction ◽

10.1154/1.2104535 ◽

2006 ◽

Vol 21 (1) ◽

pp. 45-51 ◽

Cited By ~ 10

Author(s):

Abderrahim Aatiq ◽

My Rachid Tigha ◽

Rabia Hassine ◽

Ismael Saadoune

Keyword(s):

Solid State ◽

Room Temperature ◽

Rietveld Analysis ◽

Structural Studies ◽

Hexagonal Cell ◽

Conventional Solid State Reaction ◽

Space Group ◽

X Ray ◽

Cell Parameters ◽

Crystallographic Structures

Crystallographic structures of two new orthophosphates Ca0.50SbFe(PO4)3 and CaSb0.50Fe1.50(PO4)3 obtained by conventional solid state reaction techniques at 900 °C, were determined at room temperature from X-ray powder diffraction using Rietveld analysis. The two compounds belong to the Nasicon structural family. The space group is R3 for Ca0.50SbFe(PO4)3 and R3c for CaSb0.50Fe1.50(PO4)3. Hexagonal cell parameters for Ca0.50SbFe(PO4)3 and CaSb0.50Fe1.50(PO4)3 are: a=8.257(1) Å, c=22.276(2) Å, and a=8.514(1) Å, c=21.871(2) Å, respectively. Ca2+ and vacancies in {[Ca0.50]3a[◻0.50]3b}M1SbFe(PO4)3 are ordered within the two positions, 3a and 3b, of M1 sites. Structure refinements show also a quasi-ordered distribution of Sb5+ and Fe3+ ions within the Nasicon framework. Thus, in {[Ca0.50]3a[◻0.50]3b}M1SbFe(PO4)3, each Ca(3a)O6 octahedron shares two faces with two Fe3+O6 octahedra and each vacancy (◻(3b)O6) site is located between two Sb5+O6 octahedra. In [Ca]M1Sb0.50Fe1.50(PO4)3 compound (R3c space group), all M1 sites are occupied by Ca2+ and the Sb5+ and Fe3+ ions are randomly distributed within the Nasicon framework.

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Structure of a new CaII1/3SbV1/6BiIII1/2PO4 phosphate

Powder Diffraction ◽

10.1017/s0885715613000717 ◽

2013 ◽

Vol 29 (1) ◽

pp. 14-19 ◽

Cited By ~ 1

Author(s):

Abderrahim Aatiq ◽

My Rachid Tigha

Keyword(s):

Room Temperature ◽

Structural Information ◽

Rietveld Analysis ◽

Infrared Spectroscopic Study ◽

Conventional Solid State Reaction ◽

Monoclinic System ◽

X Ray ◽

Cell Parameters ◽

Air Atmosphere ◽

Crystallographic Structures

A new Ca1/3Sb1/6Bi1/2PO4 “CaSb0.50Bi1.50(PO4)3” phosphate has been synthesized by conventional solid-state reaction techniques at 900 °C in air atmosphere. Their crystallographic structures were determined at room temperature from X-ray powder diffraction (XRPD) data using the Rietveld analysis. CaII1/3SbV1/6BiIII1/2PO4 material possesses the high-temperature BiPO4 monoclinic structure variety. It crystallizes in monoclinic system with P21/m space group and the cell parameters are: a = 4.9358(1) Å, b = 6.9953(2), c = 4.7075(1) Å, and β = 96.2(1)°. Their structure can be described as composed of alternating edge-sharing AO8 (A = Ca, Sb, Bi) bisdisphenoids and PO4 tetrahedra forming chains parallel to the b axis. Every AO8 polyhedron is surrounded by six PO4 and every PO4 tetrahedron is surrounded by six AO8 polyhedra. Infrared spectroscopic study was used to obtain further structural information.

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Synthesis and Rietveld refinements of new ceramics Sr2CaFe2WO9 and Sr2PbFe2TeO9 perovskites

Powder Diffraction ◽

10.1017/s0885715618000222 ◽

2018 ◽

Vol 33 (2) ◽

pp. 134-140 ◽

Cited By ~ 2

Author(s):

Abdelhadi El Hachmi ◽

Y. Tamraoui ◽

Bouchaib Manoun ◽

R. Haloui ◽

M.A. Elaamrani ◽

...

Keyword(s):

Room Temperature ◽

Rietveld Analysis ◽

Double Perovskites ◽

Unit Cell Parameters ◽

Rietveld Refinements ◽

X Ray ◽

Cell Parameters ◽

State Technique ◽

Xrpd Patterns ◽

Polycrystalline Form

Ceramics of Sr2CaFe2WO9 and Sr2PbFe2TeO9 double perovskites have been prepared in polycrystalline form by solid-state technique, in the air. The crystalline structure was analyzed using X-ray powder diffraction (XRPD) at room temperature. Rietveld analysis of XRPD patterns show that both compounds adopt a tetragonal structure with space group I4/m, with unit cell parameters a = 5.5453(1) Å, c = 7.8389(1) Å for Sr2CaFe2WO9, and a = 5.5994(15) Å, c = 7.8979(30) Å for Sr2PbFe2TeO9. A certain degree of anti-site disordering of W and/or Te and Fe on the B –sites have been detected, indicating the presence of a partial amount of W and/or Te at Fe positions and vice versa.

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Structure, Infrared and Raman spectroscopic studies of new AII(SbV0.50CrIII0.50)(PO4)2 (A = Ba, Sr, Pb) yavapaiite phases

Mediterranean Journal of Chemistry ◽

10.13171/mjc10802108201448hb ◽

2020 ◽

Vol 10 (8) ◽

pp. 734

Author(s):

Hajar Bellefqih ◽

Rachid Fakhreddine ◽

Rachid Tigha ◽

Abderrahim Aatiq

Keyword(s):

Diffraction Method ◽

Rietveld Analysis ◽

Spectroscopic Studies ◽

Conventional Solid State Reaction ◽

Space Group ◽

X Ray ◽

Cell Parameters ◽

Raman Spectroscopic ◽

Air Atmosphere ◽

Monoclinic Cell

Three new AII(Sb0.5Cr0.5)(PO4)2 (AII = Ba, Sr, Pb) yavapaiite phases, abbreviated as [ASbCr], have been successfully synthesized by a conventional solid-state reaction in air atmosphere. Their crystal structures have been investigated by Rietveld analysis from the X-ray powder diffraction method. Results show that Ba(Sb0.5Cr0.5)(PO4)2 crystallizes in monoclinic C2/m space group (Z = 2) with cell parameters a = 8.140(1) Å; b = 5.175(1) Å; c = 7.802(1) Å and β = 94.387(1)°. Structures of AII(Sb0.5Cr0.5)(PO4)2 (AII = Sr, Pb) compounds are comparable, and both crystallize in a distorted yavapaiite structure with C2/c space group (Z = 4). Obtained monoclinic cell parameters are: a = 16.5038(2) Å; b = 5.1632(1) Å; c = 8.0410(1) Å; β = 115.85(1) for [SrSbCr] and a = 16.684(2) Å; b = 5.156(1) Å c = 8.115(1) Å; β = 115.35(1)° for [PbSbCr]. Infrared and Raman spectroscopic study was undertaken to provide information about vibrations bonds within the studied yavapaiite materials.

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Synthesis and X-ray powder diffraction data of Ba2.64Ta11.25O30.81

Powder Diffraction ◽

10.1017/s0885715614000748 ◽

2014 ◽

Vol 29 (4) ◽

pp. 385-388 ◽

Cited By ~ 1

Author(s):

A. A. Babaryk ◽

I. V. Odynets ◽

S. Khainakov ◽

N. S. Slobodyanik

Keyword(s):

Single Phase ◽

Tungsten Bronze ◽

Rietveld Analysis ◽

Structure Type ◽

Tungsten Bronze Structure ◽

Solid State Reaction Technique ◽

Conventional Solid State Reaction ◽

Tetragonal Tungsten Bronze ◽

X Ray ◽

Cell Parameters

The Ba2.64Ta11.25O30.81was prepared by conventional solid-state reaction technique as a single phase. It was found that the compound crystallizes in the tetragonal system, space group P4/mbm (No. 127) and unit-cell parameters are a = 12.508 59(8) Å, c = 3.912 81(2) Å, V = 612.218(7) Å3, and Z = 1. The crystal structure of the Ba2.64Ta11.25O30.81 phase is found to be closely related to the tetragonal tungsten bronze structure type, comprising interstitial (TaO)+ inclusions. Reference data were derived from the Rietveld analysis and reported here.

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Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder

Materials ◽

10.3390/ma14133502 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3502

Author(s):

Fangzhou Song ◽

Masayoshi Uematsu ◽

Takeshi Yabutsuka ◽

Takeshi Yao ◽

Shigeomi Takai

Keyword(s):

Room Temperature ◽

Conduction Mechanism ◽

Lithium Ion ◽

X Ray Diffraction ◽

Temperature Conductivity ◽

Room Temperature Conductivity ◽

X Ray ◽

Nano Powder ◽

Powder Addition

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.

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MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300004580 ◽

2000 ◽

Vol 5 (S1) ◽

pp. 412-424

Author(s):

Jung Han ◽

Jeffrey J. Figiel ◽

Gary A. Petersen ◽

Samuel M. Myers ◽

Mary H. Crawford ◽

...

Keyword(s):

Room Temperature ◽

Rutherford Backscattering Spectrometry ◽

Optoelectronic Devices ◽

Lattice Parameter ◽

X Ray Diffraction ◽

X Ray ◽

Peak Energy ◽

Movpe Growth ◽

Pl Emission

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.

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Distorted chiolite crystal structures of α-Na5M3F14 (M=Cr,Fe,Ga) studied by X-ray powder diffraction

Powder Diffraction ◽

10.1154/1.1556990 ◽

2003 ◽

Vol 18 (2) ◽

pp. 128-134 ◽

Cited By ~ 4

Author(s):

A. Le Bail ◽

A.-M. Mercier

Keyword(s):

Crystal Structures ◽

Powder Diffraction ◽

Room Temperature ◽

Rietveld Refinements ◽

Space Group ◽

X Ray ◽

Precise Characterization

The crystal structures of the chiolite-related room temperature phases α-Na5M3F14 (MIII=Cr,Fe,Ga) are determined. For all of them, the space group is P21/n, Z=2; a=10.5096(3) Å, b=7.2253(2) Å, c=7.2713(2) Å, β=90.6753(7)° (M=Cr); a=10.4342(7) Å, b=7.3418(6) Å, c=7.4023(6) Å, β=90.799(5)° (M=Fe), and a=10.4052(1) Å, b=7.2251(1) Å, c=7.2689(1), β=90.6640(4)° (M=Ga). Rietveld refinements produce final RF factors 0.036, 0.033, and 0.035, and RWP factors, 0.125, 0.116, and 0.096, for MIII=Cr, Fe, and Ga, respectively. The MF6 polyhedra in the defective isolated perovskite-like layers deviate very few from perfect octahedra. Subtle octahedra tiltings lead to the symmetry decrease from the P4/mnc space group adopted by the Na5Al3F14 chiolite aristotype to the P21/n space group adopted by the title series. Facile twinning precluded till now the precise characterization of these compounds.

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Metal-Rich Metallaboranes: Synthesis, Structures and Bonding of Bi- and Trimetallic Open-Faced Cobaltaboranes

Inorganics ◽

10.3390/inorganics9040028 ◽

2021 ◽

Vol 9 (4) ◽

pp. 28

Author(s):

Kriti Pathak ◽

Chandan Nandi ◽

Jean-François Halet ◽

Sundargopal Ghosh

Keyword(s):

Electronic Structures ◽

Density Functional ◽

Room Temperature ◽

Electron Pair ◽

X Ray Diffraction ◽

Functional Theory ◽

X Ray ◽

Cluster 2 ◽

Cobalt Center

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.

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