Structures of the reduced niobium oxides Nb12O29 and Nb22O54

Details Structures of the reduced niobium oxides Nb12O29 and Nb22O54 Structures of the reduced niobium oxides Nb12O29 and Nb22O54

2007-08-05

arxiv.org/abs/0708.0673v1

J. Sol. St. Chem. 180, 2864-2870 (2007)

Physics

Condensed Matter

Materials Science

19 pages, 4 figures, accepted to J. Sol. St. Chem

Scientific paper

10.1016/j.jssc.2007.08.013

The crystal structure of Nb22O54 is reported for the first time, and the structure of orthorhombic Nb12O29 is reexamined, resolving previous ambiguities. Single crystal x-ray and electron diffraction were employed. These compounds were found to crystallize in the space groups P2/m (a = 15.7491(2) A, b = 3.8236(3) A, c = 17.8521(2) A, beta = 102.029(3)) and Cmcm (a = 3.8320(2) A, b = 20.7400(9) A, c = 28.8901(13) A) respectively and share a common structural unit, a 4x3 block of corner sharing NbO6 octahedra. Despite different constraints imposed by symmetry these blocks are very similar in both compounds. Within a block, it is found that the niobium atoms are not located in the centers of the oxygen octahedra, but rather are displaced inward toward the center of the block forming an apparent antiferroelectric state. Bond valence sums and bond lengths do not show the presence of charge ordering, suggesting that all 4d electrons are delocalized in these compounds at the temperature studied, T = 200 K.

Affiliated with

Also associated with

No associations

Rating

Structures of the reduced niobium oxides Nb12O29 and Nb22O54 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Structures of the reduced niobium oxides Nb12O29 and Nb22O54, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structures of the reduced niobium oxides Nb12O29 and Nb22O54 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-533828