Structural consequences of the coupled substitution of Eu,S in calcium sulfoapatite

Suitch, P. R.; Taïtaï, A.; Lacout, J.L.; Young, R. A.

doi:10.1016/0022-4596(86)90177-5

Cited by 27 publications

(13 citation statements)

References 12 publications

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“…For example, the substitution of Eu for Ca in calcium sulfoapatite, Ca 10Àx Eu x (PO 4 ) 6 S 1+x/2 [x ¼ 021:3] changes the space group from P6 3 /m to P6 3 and it has been confirmed by Rietveld refinements [18]. This is due to the changes in the various Ca-O and P-O distances by the introduction of Eu 3+ and S 2À and this results in the loss of mirror plane and two different environments for the Ca(1) site itself, namely Ca(1a) and Ca(1b).…”

Section: Introductionmentioning

confidence: 77%

Eu3+ luminescence—a structural probe in BiCa4(PO4)3O, an apatite related phosphate

Lakshminarasimhan

Varadaraju

2004

Journal of Solid State Chemistry

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Section: Introductionmentioning

confidence: 77%

Eu3+ luminescence—a structural probe in BiCa4(PO4)3O, an apatite related phosphate

Lakshminarasimhan

Varadaraju

2004

Journal of Solid State Chemistry

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“…1). However, in some rare earth silicates with the apatite structure, the formula can be written as RE9.33[~10.67(5iO4) 602 (1) where ~ represents cation vacancies [9]. Because of the existence of cation vacancies, there is space to fill these vacancies and introduce extra oxygen into the crystal lattice.…”

Section: Introductionmentioning

confidence: 99%

“…; Z, Z' = F-, CI-, I, OH-; O 2-, S z-etc. [1][2][3][4][5][6][7][8]. Some materials with apatite structure (S.G. P63/m ) exhibit quite high cationic (H +, Li +, Na § K + etc.)…”

Section: Introductionmentioning

confidence: 99%

Synthesis and ionic conduction of apatite-type materials

Tao

Irvine

2000

Ionics

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Abstract. Apatite is a mineral with general formula Ml0(XO4)6Z2, where M are metallic elements such as Li § Na +, K*, Ca 2 § Sr z+, Ba 2 § Ln 3 § etc.; X = P, V, S, Si, Ge, Re, Cr etc; Z = F-, CI-, I-, OH-, O z-, S a-etc. Some materials with apatite structure (S.G. P63/m) exhibit quite high cationic (Li § H § etc.) and/or anionic (F-, C1-etc.) conduction. Recently, it was reported that some rare earth silicates, e.g., Lam(SiO4)603, exhibit quite high oxide-ion conductivity. In this paper, we discuss chemical composition, structure, synthetic procedure and ionic conduction of apatite-type materials. Recent improvements are briefly reviewed. High ionic conductivity has been observed for both cation deficient, oxygen stoichiometric La9.33(5iO4)60 a and cation stoichiometric, oxygen excess Lalo(SiO4)603 compositions. Grain boundary conductivity is usually low, which tends to dominate the impedance response. The resistance, particularly the grain boundary resistance is also found to depend on pO a.

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“…Concerning synthetic phases, we quote other possible space * E-mail: manuela.rossi@unina.it groups in which apatite can grow: for instance, "sulfoapatites" (with S at the X site) show hexagonal space group P6 3 (Sutich et al 1986), "oxyapatites" [Ca 10 (PO 4 ) 6 O, Henning et al 1999], and "carbonate apatites" (Suetsugu et al 2000) show hexagonal space group P6; less common examples of trigonal P3 apatites (Fleet and Liu 2003) also occur.…”

Section: Introductionmentioning

confidence: 99%

Crystal-chemical and structural characterization of fluorapatites in ejecta from Somma-Vesuvius volcanic complex

Rossi

Ghiara

Chita

et al. 2011

American Mineralogist

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The mineralogy and crystal chemistry of apatites occurring in 14 ejecta of historical eruptions (1631 and 1872 A.D.) of the Somma-Vesuvius volcanic complex were investigated by a multi-methodological approach including polarized optical microscopy, scanning electron microscope, electron microprobe analysis in wavelength-dispersive mode, laser ablation inductively coupled plasma mass spectroscopy, and single-crystal X‑ray diffraction. Five different groups of apatite, with different mineralogical and crystal-chemical features, were identified. Apatite crystals occur with well-developed hexagonal prismatic habit and, more rarely, with skeletal acicular forms. The crystals are yellow (type 1), transparent and colorless (type 2 and type 3), green (type 4) and aquamarine colored (type 5), with different paragenesis: macro-crystalline aggregates of clinopyroxenes, phlogopite, and apatite (type 1; type 4); clusters of apatite with micro-crystalline clinopyroxene, minerals of the cancrinite group, feldspars, and opaque minerals (type 2); aggregates of apatite, sellaite, wagnerite, gypsum, and phlogopite (type 3); aggregates of davyne, nepheline, mica group minerals, and apatite (type 5). Chemical analyses of apatites show variable amounts of Na, REE, Mg, Sr, and Fe replacing Ca, not negligible amounts of Si and S substituting P, and a significant substitution of Cl and OH instead of F. Five crystals representative of each apatite-type were studied by single-crystal X‑ray diffraction. Their crystal structure was refined in the hexagonal P63/m space group. A significant variation of the unit-cell parameters with the composition was observed. A comparative crystal-chemical analysis between apatites from Somma-Vesuvius and those from other localities is carried out

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Structural consequences of the coupled substitution of Eu,S in calcium sulfoapatite

Cited by 27 publications

References 12 publications

Eu3+ luminescence—a structural probe in BiCa4(PO4)3O, an apatite related phosphate

Eu3+ luminescence—a structural probe in BiCa4(PO4)3O, an apatite related phosphate

Synthesis and ionic conduction of apatite-type materials

Crystal-chemical and structural characterization of fluorapatites in ejecta from Somma-Vesuvius volcanic complex

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