Synthesis and crystal structure of a new oxychalcogenide La5Ti∼3.25Zr∼0.25S5O9.25

✍ Scribed by V. Meignen; A. Meerschaut; L. Cario; A. Lafond

• Book ID: 104029203
• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 408 KB
• Volume: 178
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2005.03.003

✦ Synopsis

A new phase in the quinary system La/Ti/Zr/S/O was obtained from a mixture of La 2 O 3 , La 2 S 3 , ZrO 2 , and TiO 2 by a solid-state reaction at 1273 K in a sealed fused-silica tube. The structure of this new phase, La 5 Ti $3.25 Zr $0.25 S 5 O 9.25 , was solved by singlecrystal X-ray diffraction, with R ðobsÞ ¼ 3:37% for 2764 reflections (I43sðIÞ) and 125 variables. This compound crystallizes with four formula units in the monoclinic space group C2/m with lattice constants a ¼ 18:401ð2Þ ( A; b ¼ 3:9032ð3Þ ( A; c ¼ 21:944ð3Þ ( A; and b ¼ 106:100ð8Þ1: The structure can be viewed as a 2D building constituted from two-atom-thick slabs of rock salt type ( ¼ sulfide part) which are interleaved with double-octahedral chains centered on titanium/zirconium atoms (mixed Ti/Zr sites) and drawing a zigzag arrangement ( ¼ oxide part). In addition, EDXS analyses show that a solid solution Ti/Zr exists with a general formulation La 5 Ti 3.5Àx Zr x S 5 O 9.25 (where 0.1pxp0.5).