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Anion order in perovskite oxynitrides.
- Source :
-
Nature Chemistry . Jan2011, Vol. 3 Issue 1, p47-52. 6p. - Publication Year :
- 2011
-
Abstract
- Transition-metal oxynitrides with perovskite-type structures are an emerging class of materials with optical, photocatalytic, dielectric and magnetoresistive properties that may be sensitive to oxide-nitride order, but the anion-ordering principles were unclear. Here we report an investigation of the representative compounds SrMO2N (M = Nb, Ta) using neutron and electron diffraction. This revealed a robust 1O/2(O0.5N0.5) partial anion order (up to at least 750 °C in the apparently cubic high-temperature phases) that directs the rotations of MO4N2 octahedra in the room-temperature superstructure. The anion distribution is consistent with local cis-ordering of the two nitrides in each octahedron driven by covalency, which results in disordered zigzag M-N chains in planes within the perovskite lattice. Local structures for the full range of oxynitride perovskites are predicted and a future challenge is to tune properties by controlling the order and dimensionality of the anion chains and networks. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ANIONS
*PEROVSKITE
*TRANSITION metals
*NEUTRONS
*ELECTRONS
*NITRIDES
Subjects
Details
- Language :
- English
- ISSN :
- 17554330
- Volume :
- 3
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Nature Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 55835621
- Full Text :
- https://doi.org/10.1038/nchem.908