A New Series of Tungstoniobium Monophosphates with an Intersecting Tunnel Structure Closely Related to ReO3:ANb4WO9(PO4)3(A=K, Rb, Cs), KLiNb5O9(PO4)3, and KLi1−x(Nb, W)5O9(PO4)3

✍ Scribed by D. Mezaoui; M.M. Borel; A. Leclaire; A. Rebbah; J. Provost; B. Raveau

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 741 KB
• Volume: 136
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7712

✦ Synopsis

A new series of tungstoniobium monophosphates, ANb 4 WO 9 (PO 4 ) 3 (A ‫؍‬ K, Rb, Cs), KLiNb 5 O 9 (PO 4 ) 3 , and KLi 1؊x (Nb, W) 5 O 9 (PO 4 ) 3 , has been synthesized. They all crystallize in the space group Pbam with a+ +15.5 A s , b+ +10.4 A s , c+ +10.5 A s . Their original intersecting channel structure involving tunnels running along b and c is described by [M 4 P 2 O 19 ] layers parallel to (001) interconnected through [MPO 8 ] chains. In fact the MO 6 octahedra form a distorted perovskite 3D framework where some octahedra are missing. The study of the transport properties of this phase shows linear behavior for Ln vs T ؊1/4 , characteristic of variable, range-hopping conductivity.