A Powder Neutron Diffraction Study of Semiconducting and Metallic Niobium Dioxide
Abstract
Rietveld analysis of neutron powder diffraction patterns from niobium dioxide at 295 and 1300 K have been performed. At 1300 K NbO2 adopts a rutile-type structure (P42/mnm, a = 4.8463 Å, c = 3.0315 Å, x = 0.2924), whereas the room temperature form can be described as a superstructure with a subcell of the rutile type (I41/a, a = 13.7020 Å, c = 5.9850 Å). Both the c axis and the oxygen position parameter in the rutile phase are anomalously small compared with other rutile dioxides. This can be rationalized in terms of M-M bonding. Both the niobium and the oxygen thermal displacement are large in the rutile phase.
- Publication:
-
Journal of Solid State Chemistry France
- Pub Date:
- November 1994
- DOI:
- 10.1006/jssc.1994.1334
- Bibcode:
- 1994JSSCh.113....9B