Structure, infrared and Raman spectroscopic studies of new Sr0.50SbFe(PO4)3 and SrSb0.50Fe1.50(PO4)3 Nasicon phases

Tigha

2013

Powder Diffr.

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Crystallographic structures of the three NaSbR(PO 4 ) 3 (R = Cr, Fe, In) phases were determined at room temperature from X-ray powder diffraction (XRD) data using the Rietveld analysis. The three compounds belong to the Nasicon structural family. The presence of the (303) reflection in all XRD spectra of NaSbR(PO 4 ) 3 shows clearly that all compounds crystallise in rhombohedral system with R 3 space group. Na atoms are practically ordered within the two positions, 3a and 3b, of M1 sites. Structure refinements show also a partially-ordered distribution of Sb 5+ and R 3+ ions within the Nasicon framework. A Raman and Infrared spectroscopic study was used to obtain further structural information about the nature of bonding in NaSbR(PO 4 ) 3 (R = Cr, Fe, In) phases.

supporting

confidence: 88%

Section: Raman and Infrared Spectroscopysupporting

confidence: 68%

Structural and spectroscopic study of NaSbR(PO₄)₃ (R = Cr, Fe, In) phases

Tigha

2013

Powder Diffr.

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“…In order to clarify this assumption, a quantitative phaseanalysis using the Rietveld method (RQXRD) of selected compositions of the Sr (0.5+x) Sb (1−x) Fe (1+x) (PO 4 ) 3 system has been undertaken. In all cases, Rietveld refinement was carried out using a two-phase model, consisting of [Sr 0.5 ] and [Sr 1 ] Initial starting parameters for the Reitveld refinements of the four selected compositions of Sr (0.5+x) Sb (1−x) Fe (1+x) (PO 4 ) 3 system were based upon the already above mentioned crystallographic results [9]. During the course of refinement, all variables parameters such atomic coordinates and cell parameter were allowed to vary.…”

Section: Resultsmentioning

confidence: 99%

“…1". Recently, the structural characteristics by powder X-ray diffraction (XRPD) study using the Rietveld method for A 0.50 SbFe(PO 4 ) 3 (R3 space group) and ASb 0.50 Fe 1.50 (PO 4 ) 3 phases (R3c space group) (A = Ca, Sr) were realised [8,9]. In all A 0.50 SbFe(PO 4 ) 3 samples, A 2+ cations occupied principally one-half of the M1 3a sites and the Sb 5+ and Fe 3+ cations are orderly distributed within the SbFe(PO 4 ) 3 framework.…”

Section: Introductionmentioning

confidence: 99%

A Reitveld quantitative XRD phase-analysis of selected composition of the Sr_(0.5+x)Sb_(1−x)Fe_(1+x)(PO₄)₃(0 < x < 0.50) system

MATEC Web of Conferences

Tigha

Attaoui

et al. 2013

Abstract. Qualitative XRD phase-analysis of four (x = 0.10, 0.20, 0.30, 0.40) selected compositions of the Sr (0.5+x) Sb (1−x) Fe (1+x) (PO 4 ) 3 (0 < x < 0.50) system was undertaken. XRD data shows the absence of a continuously solid solution. In fact, each composition is composed only of a mixture of the two end members, Sr 0.50 SbFe(PO 4 ) 3 (R3 space group) and SrSb 0.50 Fe 1.50 (PO 4 ) 3 (R3c space group), type-phases. Rietveld refinement method, using the XRPD technique, has been used for a quantitative phase-analysis of these compositions. In order to evaluate the relative errors of this experimental result, a set of standard phase-mixtures of both end compositions of the system was also quantified by the Rietveld method. Obtained results show the usefulness of this method for quantitative phase-analysis, particularly in geology including other classes of materials such clay and cement.

“…As a result of various cationic substitution in A sites of A III PO4 phases, a new family of oxides crystallising in several basic types as Monazite, Zircon (Xenotime), Scheelite, Cheralite, Nasicon and Yavapaiite compounds type have been synthesized and characterized [1][2][3][4][5][6][7][8][9][10][11][12][13][14] . Such materials can include a mixing of A II /M IV ions leading to the A II 0.5M IV 0.5PO4 formula which was often reported as A II M IV (PO4)2 form (A = Ca, Sr, Ba, Pb; M = Ti, Ge, Zr, Mo, Sn, Th, U, Np, Pu) [3][4][5][6][7][8] .…”

Section: Introductionmentioning

confidence: 99%

Structure, Infrared and Raman spectroscopic studies of the new Ba(NbV 0.5MIII0.5)(PO4)2 (MIII = Al, Cr, Fe, In) yavapaiite compounds ‘series

Fakhreddine

2019

Mediterr.J.Chem.,

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Synthesis and structural study of the new Ba(NbV 0.50MIII 0.50)(PO4)2 (MIII = Al, Cr, Fe, In) phosphates, abbreviated as [BaNbM], were reported here for the first time. Structures of [BaNbM] compounds, obtained by solid-state reaction in air atmosphere, were determined at room temperature from X-ray powder diffraction using the Rietveld method. The four studied compoundsfeature the yavapaiite-type structure, with space group C2/m ( 3 C2h , N°12) and Z = 2. Their framework can be described as consisting of dense slabs of Nb(M)O6 octahedra and PO4 tetrahedra interconnected via corner-sharing, alternating along the c-axis with layers of Ba cations in ten-fold coordination. Raman and Infrared spectroscopic study were used to obtain further structural information about the nature of bonding in selected compositions. Assignments of Nb-O, M-O and P-O Raman and Infrared bands, in [BaNbM] compounds, were based on those already known in the literature for niobium and phosphates oxides. Some empirical relationships, connecting Raman stretching frequencies to the obtained Nb-O and P-O distance values, were also used for assignments of various Raman bands