Synthesis, Structure, and Physical Studies of the New β-LiVOAsO4 Compound

✍ Scribed by J. Gaubicher; F. Orsini; T. Le Mercier; S. Llorente; A. Villesuzanne; J. Angenault; M. Quarton

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 383 KB
• Volume: 150
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8562

✦ Synopsis

Two new compounds of the A x MOXO 4 family, -LiVOAsO 4 and -VOAsO 4 , have been synthesized by solid state reaction and electrochemical lithium deintercalation from -LiVOAsO 4 , respectively. Both compounds are isostructural and are built like other -VOXO 4 (X ‫؍‬ S, P) by (VO 5 ) chains of distorted VO 6 octahedra connected via corner-shared AsO 4 tetrahedra. For -LiVOAsO 4 the additional Li ؉ ions occupy chains of edgeshared octahedra running perpendicularly to the (VO 5 ) chains. The one-dimensional antiferromagnetic behavior suggested by the structure has been experimentaly con5rmed. It is shown that lithium deintercalation occurs through a 5rst-order transition at 4.02 V vs Li ؉ /Li 0 . From chemical bond considerations it is shown why the redox potential of a given transition element M in a six-fold coordination involving (M ‫؍‬ O) m؉ units lies between those observed in oxides and in M 2 (XO 4 ) 3 compounds with (XO 4 ) n؊ oxo anions (X ‫؍‬ S, P, As).