New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs1-xPxO4 (0 <= x <= 1)

摘要

LiTiOAs1-xPxO4 (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 LiTiOAs1-xPxO4 (X = 0, 0.5 and 1) samples determined by Rietveld analysis is orthorhombic with Pmna space group. It is formed by a 3D network of TiO6 octahedra and XO4 (X = As1-xPx) 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 angstrom) and long (2.301-2.275 angstrom) Ti-O bonds. Raman and infrared studies confirm the existence of Ti-O-Ti chains. Thermal stability of LiTiOASO(4) has been reported. (c) 2005 Elsevier Inc. All rights reserved.