Synthesis, crystal structure and optical investigation of the new phosphates: Na{sub 7}Mg{sub 13}Ln(PO{sub 4}){sub 12} (Ln=La, Eu)

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.05.010· OSTI ID:21421572

Jerbi, Hasna; Hidouri, Mourad ^[1]; Glorieux, Benoit; Darriet, Jacques; Garcia, Alain; Jubera, Veronique ^[2]

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1. UR: Materiaux Inorganiques, Departement de Chimie, Faculte des Sciences, 5019 Monastir (Tunisia)
2. CNRS, Universite de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac, F-33608 (France)

Two new isostructural rare earth phosphates Na{sub 7}Mg{sub 13}Ln(PO{sub 4}){sub 12} (Ln=La, Eu) have been synthesized and investigated by X-ray diffraction and optical measurements. They crystallize in the orthorhombic system with the Cmc2{sub 1} space group (Z=4). The crystal structure exhibits a new type of framework built up from LnO{sub 8} (Ln=La, Eu), MO{sub 6} (M=0.5Mg+0.5Na) and MgO{sub x} (x=5, 6) polyhedra and PO{sub 4} tetrahedra linked by common corner, edge or face. It can be described in terms of [Mg{sub 4}MP{sub 4}O{sub 22}]{sub {infinity}} layers stacked along the a direction. These layers are interconnected by [Mg{sub 4}LnP{sub 4}O{sub 36}]{sub {infinity}} undulating chains spreading along the b direction. This framework delimits 6 distinct cavities occupied by Na{sup +} cations. The results of the optical study of Na{sub 7}Mg{sub 13}La{sub 1-x}Eu{sub x}(PO{sub 4}){sub 12} (x=0, 0.02, 0.1, 1) reveal the presence of two different Eu{sup 3+} ion environments whereas the X-ray study predicts the existence of only one Eu site. This difference can be explained by the possible presence of the europium element in the sodium sites with small occupancies which cannot be detected by the X-ray structural determination. - Graphical abstract: Emission spectra of Na{sub 7}Mg{sub 13}Eu(PO{sub 4}){sub 12} and Na{sub 7}Mg{sub 13}La{sub 0.9}Eu{sub 0.1}(PO{sub 4}){sub 12} compounds for {lambda}{sub exc}=240, 290 and 393.2 nm.

• OSTI ID: 21421572
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 8; Other Information: DOI: 10.1016/j.jssc.2010.05.010; PII: S0022-4596(10)00199-4; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EMISSION SPECTRA
EUROPIUM IONS
EUROPIUM PHOSPHATES
LANTHANUM PHOSPHATES
LAYERS
MAGNESIUM COMPOUNDS
OPTICAL PROPERTIES
ORTHORHOMBIC LATTICES
SODIUM COMPOUNDS
SODIUM IONS
SPACE GROUPS
SYNTHESIS
X-RAY DIFFRACTION
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
EUROPIUM COMPOUNDS
IONS
LANTHANUM COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SPECTRA
SYMMETRY GROUPS