New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs_1−xP_xO₄ (0 ≤ x ≤ 1)

Mohamed Chakir (1) , Abdelaziz El Jazouli (1) , Jean-Pierre Chaminade (2) , Françoise Bourée (3) , Danita de Waal (4)

1 Laboratoire de Chimie des Matériaux Solides
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 LLB - UMR 12 - Laboratoire Léon Brillouin
4 Department of Chemistry

LiTiOAs_1−xP_xO₄ (0 ≤ x ≤ 1) compounds have been prepared using solutions of Li, Ti, As and P elements as starting products. Selected compositions have been investigated by powder X-ray or neutrons diffraction analysis, Raman and infrared spectroscopy. The structure of LiTiOAs_1−xP_xO₄ (x=0, 0.5 and 1) samples determined by Rietveld analysis is orthorhombic with Pnma space group. It is formed by a 3D network of TiO₆ octahedra and XO₄ (X=As_1−xP_x) tetrahedra where octahedral cavities are occupied by lithium atoms. TiO₆ octahedra are linked together by corners and form infinite chains along a-axis. Ti atoms are displaced from the centre of octahedral units in alternating short (1.700–1.709 Å) and long (2.301–2.275 Å) Ti–O bonds. Raman and infrared studies confirm the existence of Ti–O–Ti chains. Thermal stability of LiTiOAsO₄ has been reported.

Mots clés: Structure; Powder diffraction; X-rays; Neutrons; Raman; Infrared

Domaines: Matériaux

Mohamed Chakir, Abdelaziz El Jazouli, Jean-Pierre Chaminade, Françoise Bourée, Danita de Waal. New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs_1−xP_xO₄ (0 ≤ x ≤ 1). Journal of Solid State Chemistry, 2006, 179 (1), pp.18-28. ⟨10.1016/j.jssc.2005.09.047⟩. ⟨hal-00436047⟩