Structures of two newly synthesized A0.50SbFe(PO4)3 (A=Mn, Cd) Nasicon phases

2005 ◽  
Vol 20 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Abderrahim Aatiq ◽  
Rabia Hassine ◽  
My Rachid Tigha ◽  
Ismael Saadoune
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
Cation Distribution ◽  
Room Temperature ◽  
Rietveld Method ◽  
Hexagonal Cell ◽  
X Ray ◽  
Cell Parameters ◽  
Two Samples

Crystal structures of A0.50SbFe(PO4)3(A=Mn, Cd) phases, obtained by solid state reaction at 920 °C, were determined at room temperature from X-ray powder diffraction (XRD) using the Rietveld method. The structures of the two samples are of the Nasicon-type with the R3 space group. Hexagonal cell parameters for A=Mn and Cd are: a=8.375(1) Å, c=21.597(2) Å and a=8.313(1) Å, c=21.996(2) Å, respectively. From XRD data, it is difficult to unambiguously distinguish between Cd2+ and Sb5+ ions in Cd0.50SbFe(PO4)3 and between Mn2+ and Fe3+ cations in Mn0.50SbFe(PO4)3. Nevertheless the overall set of cation–anion distances within the Nasicon framework clearly shows that the cation distribution can be illustrated by the {[A0.50]3a[◻0.50]3b}M1SbFe(PO4)3 (A=Mn, Cd) crystallographic formula. The divalent A2+ cations and vacancies are ordered within the two positions, 3a and 3b, of the M1 sites. Structure refinements show also a quasi-ordered distribution of Sb5+ and Fe3+ ions within the Nasicon framework. Thus, each A(3a)O6(A=Mn, Cd) octahedron shares two faces with two Fe3+O6 octahedra and each vacancy (◻(3b)O6) site is located between two Sb5+O6 octahedra.

Crystal structures of newly synthesized SbV1.50FeIII0.50(PO4)3 and (SbV0.50FeIII0.50)P2O7

2007 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Abderrahim Aatiq ◽  
Rachid Bakri
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Rietveld Method ◽  
Hexagonal Cell ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Air Atmosphere

Synthesis and structure of two phosphates belonging to the ternary Sb2O5-Fe2O3-P2O5 system are reported. Structures of both SbV1.50FeIII0.50(PO4)3 and (SbV0.50FeIIIe0.50)P2O7 phases, obtained by solid state reaction in air atmosphere at 950 °C and 900 °C, respectively, were determined at room temperature from X-ray powder diffraction using the Rietveld method. Sb1.50Fe0.50(PO4)3 phosphate belongs to the Nasicon-type structure with R32 space group. Hexagonal cell parameters are ahex.=8.305(1) Å and chex.=22.035(2) Å. Rietveld refinement results show a 2-2 ordered distribution, along the c-axis, of X(1) and X(2) sites (crystallographic formula [Sb0.88Fe0.12]X(1)[Fe0.38Sb0.62]X(2)(PO4)3) in the Nasicon framework. (Sb0.50Fe0.50)P2O7 is isotypic with β-SbP2O7 pyrophosphate [Pna21 space group; a=7.865(1) Å, b=15.699(2) Å, c=7.847(1) Å]. Its crystal structure is built up from corner-shared SbO6 or FeO6 octahedra and P2O7 groups (two group types). Each P2O7 group shares its six vertices with three SbO6 and three FeO6 octahedra, and each octahedra is connected to six P2O7 groups. A quasi 1-1 ordered distribution, along the b-axis, of Sb5+ and Fe3+ ions in the pyrophosphate framework are observed.

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

2006 ◽  
Vol 21 (1) ◽  
pp. 45-51 ◽  
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.

X-ray powder diffraction studies of a new compound: Th13Te24O74

2002 ◽  
Vol 17 (1) ◽  
pp. 32-36 ◽  
Author(s):  
S. N. Tripathi ◽  
S. N. Achary ◽  
P. N. Namboodiri
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Direct Solid ◽  
Measured Density

The compound Th13Te24O74 was prepared by three independent methods, namely, thermal decomposition of ThTe2O6 in oxygen and argon and direct solid-state reaction of ThO2 and TeO2. The X-ray powder diffraction patterns of the three products, by and large, are similar, except for some differences in intensities and extra diffraction lines. The thermal decomposition of ThTe2O6 was carried out in the streams of oxygen and argon by thermogravimetry at a heating rate of 5 K/min in the temperature range of 725–840 °C. The solid-state reaction of ThO2 and TeO2 (13:24) was carried out in a sealed ampoule at 700 °C. The measured density of this compound is 8.23 g/cm3. An orthorhombic lattice with unit cell parameters, a=11.310±0.005 Å, b=14.064±0.006 Å, c=9.056±0.004 Å, and volume of 1440.419±1.088 (Å)3 was determined for this compound.

Preparation and crystal structure of SbV1.50InIII0.50(PO4)3 and (SbV0.50InIII0.50)P2O7

2008 ◽  
Vol 23 (3) ◽  
pp. 232-240
Author(s):  
Abderrahim Aatiq ◽  
Rachid Bakri ◽  
Aaron Richard Sakulich
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Room Temperature ◽  
Rietveld Method ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Synthesis and structure of two phosphates belonging to the ternary Sb2O5–In2O3–P2O5 system are realized. Structures of SbV1.50InIII0.50(PO4)3 and (SbV0.50InIII0.50)P2O7 phases, obtained by solid state reaction in air at 950 °C, were determined at room temperature from X-ray powder diffraction using the Rietveld method. SbV1.50InIII0.50(PO4)3 have a monoclinic (space group P21/n) distortion of the Sc2(W O4)3-type framework. Its structure is constituted by corner-shared SbO6 or InO6 octahedra and PO4 tetrahedra. Monoclinic unit cell parameters are a=11.801(2) Å, b=8.623(1) Å, c=8.372(1) Å, and β=90.93(1)°. (Sb0.50In0.50)P2O7 is isotypic with (Sb0.50Fe0.50)P2O7 and crystallizes in orthorhombic system (space group Pna21) with a=7.9389(1) Å, b=16.0664(2) Å, and c=7.9777(1) Å. Its structure is built up from corner-shared SbO6 or InO6 octahedra and P2O7 groups (two group-types). Each P2O7 group shares its six vertices with three SbO6 and three InO6 octahedra, and each octahedron is connected to six P2O7 groups.

Structure of AFeTi(PO4)3 (A=Ca,Cd) Nasicon phases from powder X-ray data

2004 ◽  
Vol 19 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Abderrahim Aatiq ◽  
Hicham Dhoum
Keyword(s):  
Solid State ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Rietveld Analysis ◽  
Nasicon Structure ◽  
X Ray Diffraction ◽  
Hexagonal Cell ◽  
X Ray ◽  
Cell Parameters ◽  
Anion Distance

AFeTi(PO4)3 (A=Ca,Cd) materials were obtained by solid state reaction in air at 1000 °C. Structures of the two compounds were determined from X-ray diffraction data using Rietveld analysis. Both phases exhibit the Nasicon-type structure (R3¯c space group) with a statistical Fe(Ti) distribution within the framework. Their hexagonal cell parameters are a=8.518(1) Å, c=21.797(2) Å and a=8.534(1) Å, c=21.416(2) Å, for CaFeTi(PO4)3 and CdFeTi(PO4)3, respectively. Cd atoms occupy the M1 site in CdFeTi(PO4)3. From XRD data, it is difficult to distinguish without ambiguity between Ca2+ and Ti4+ ions in CaFeTi(PO4)3. Nevertheless from the cation–anion distance found after the structure determination, Ca2+ distribution within the M1 site of Nasicon structure are validated.

Crystal and X-Ray Powder Data for Three Orthovanadates M Th2 (VO4)3 (M = K, Rb, Cs)

1989 ◽  
Vol 4 (3) ◽  
pp. 165-167 ◽  
Author(s):  
A. Elfakir ◽  
J.P. Souron ◽  
M. Quartern
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters

AbstractThree isotopic orthovanadates MTh2 (VO4)3 with M = K, Rb, Cs have been syndiesized by solid state reaction. Single crystals of K Th2 (VO4)3 and Rb Th2 (VO4)3 were obtained. These compounds are isotypic with the corresponding orthophosphates: monoclinic, space group C2/c, Z = 4. Unit-cell parameters for die diree compounds were determined. Powder diffraction data for each phase are reported.

Crystal and Powder X-Ray Diffraction Data for TlBeXO4 (X = P, As)

1992 ◽  
Vol 7 (1) ◽  
pp. 44-46 ◽  
Author(s):  
G. Wallez ◽  
A. Elfakir ◽  
M. Quartern
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
New Compounds

AbstractTwo new compounds TlBeXO4 (X = P, As) have been synthesized by solid state reaction. Single crystals were obtained. These compounds are isotypic, space group Pna21, Z = 4. Unit-cell parameters were determined. Powder diffraction data for each phase are reported.

Determining the crystal structure of Sr5(PO4)3Br, a new compound in the apatite series, by powder diffraction modeling

1998 ◽  
Vol 13 (2) ◽  
pp. 70-73 ◽  
Author(s):  
Dagmar Nötzold ◽  
Harm Wulff
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
Figure Of Merit ◽  
Rietveld Method ◽  
Structure Model ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Parameters ◽  
Atomic Parameters

Pentastrontium bromidephosphate, Sr5(PO4)3Br, was prepared by solid state reaction. The crystal structure of polycrystalline Sr5(PO4)3Br was refined from X-ray powder diffraction data by the Rietveld method using the structure model of Sr5(PO4)3Cl single crystals. Sr5(PO4)3Br is isostructural with Sr5(PO4)3Cl. The space group is P63/m. The cell parameters are a0=9.9641(1) Å, c0=7.2070(1) Å, α=β=90°, γ=120°, Z=2, d(calc)=4.27 g/cm3, and d(expt)=4.10 g/cm3. Atomic parameters are given. Final values are Rp=10.9%, Rwp=14.3%, and S=1.28. The figure of merit is F30=58 (0.013, 39).

H2/N2 MIXTURE ATMOSPHERE EFFECTS ON THE BEHAVIOR OF THE DOUBLE PEROVSKITE COMPOUND Sr2CoMoO6

2008 ◽  
Vol 22 (21) ◽  
pp. 3579-3588 ◽  
Author(s):  
A. AZIZI ◽  
A. KAHOUL ◽  
G. SCHMERBER ◽  
S. COLIS ◽  
A. DINIA
Keyword(s):  
Magnetic Susceptibility ◽  
Solid State ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Double Perovskite ◽  
Gas Mixture ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters

Sr 2 CoMoO 6 and Sr 2 CoMoO 6-δ ceramics have been obtained by solid state reaction in air and in a H 2/ N 2 gas mixture. At room temperature, as shown by X-ray diffraction, both compounds have a tetragonal perovskite-like structure with doublet unit-cell parameters, space group I4/m, with a = 5.5575, c = 7.9342 in Sr 2 CoMoO 6 and a = 5.5683 and c = 7.9395 in Sr 2 CoMoO 0.95. The latter contains small traces of Co and SrCoO 2.61, with an almost expansion. The magnetic susceptibility indicates that Sr 2 CoMoO 6 is an antiferromagnet with TN = 37 K. The magnetization was found to be the same in both samples, while the electric properties, originating from the oxygen content, are drastically affected.

X-Ray Powder Diffraction Data for AITh2(VO4)3Compounds with AI= Li, Na, Ag

1990 ◽  
Vol 5 (4) ◽  
pp. 219-220 ◽  
Author(s):  
A. Elfakir ◽  
J.P. Souron ◽  
M. Quarton
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Zircon Type

AbstractThree orthovanadates ATh2(VO4)3with A = Li, Na, Ag have been synthesized by solid state reaction. Single crystals of AgTh2(VO4)3were obtained. This compound is isotypic with sheelite whose space group is I41/a(88). The two other compounds (A = Li, Na) have a zircon type structure: I41/ amd(141). Unit-cell parameters and powder diffraction data for the three compounds are reported.

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