Synthesis, crystal structure and vibrational spectra characterization of MILa(PO3)4 (MI = Na, Ag)

Mohamed El Masloumi (1) , Inhar Imaz (1) , Jean-Pierre Chaminade (1) , Jean-Jacques Videau (1) , Michel Couzi (2) , Mohamed Mesnaoui (3) , Mohamed Maazaz (3)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 LPCM - Laboratoire de Physico-Chimie Moléculaire
3 Laboratoire de Chimie du Solide Minéral

The single crystals of lanthanum metaphosphate MLa(PO3)4 (M=Na, Ag) have been synthesized and studied by a combination of X-ray crystal diffraction and vibrational spectroscopy. The sodium and silver compounds crystallize in the same monoclinic P21/n space group ( factor group) with the following respective unit cell dimensions: a=7.255(2), b=13.186(3), , β=90.40(2)°, , Z=4 and a=7.300(5), b=13.211(9), , β=90.47(4)°, , Z=4. This three-dimensional framework is built of twisted zig-zag chains running along a direction and made up of PO4 tetrahedra sharing two corners, connected to the LaO8 and NaO7 or AgO7 polyhedra by common oxygen atoms to the chains. The infrared and Raman vibrational spectra have been investigated. A group factor analysis leads to the determination of internal modes of (PO3)− anion in the phosphate chain.

Mots clés: Crystal structure; Phosphate; Sodium; Silver; Lanthanum; Vibrational spectra

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Mohamed El Masloumi, Inhar Imaz, Jean-Pierre Chaminade, Jean-Jacques Videau, Michel Couzi, et al.. Synthesis, crystal structure and vibrational spectra characterization of MILa(PO3)4 (MI = Na, Ag). Journal of Solid State Chemistry, 2005, 178, n° 11, pp.3581-3588. ⟨10.1016/j.jssc.2005.09.011⟩. ⟨hal-00014627⟩