Synthesis, superconducting properties and structural (including electron diffraction) studies of Nax Nb O2 and Lix Nb O2
- 1. Stockholm Univ. (Sweden)
Description
Monophasic Nax Nb O2 (x=0.5 - 0.6), (transition temperature Tc ≅ 4,1 K) was prepared by solid state reaction between Na3 Nb O4 and Nb. X-ray powder diffraction data from a monophasic sample were used for a refinement of the structure of Na0.5 Nb O2 (Rp=7.4% and RI=5.3%), using the Rietveld method. At low x-values a closely related second phase can occur. Rietveld refinement using X-ray powder diffraction data showed this phase to be isostructural with Na Nb O2 but with the chemical formula Na0.1 Nb O2. Transmission electron microscopy studies of Nax Nb O2 and Lix Nb O2 revealed the presence of superstructures in some crystallites. The electron diffraction patterns resemble to some extent those reported for transformations among tantalum chalcogenides. (authors). 35 refs., 12 figs., 1 tab
Additional details
Publishing Information
- Journal Title
- European Journal of Solid State and Inorganic Chemistry
- Journal Volume
- 33
- Journal Issue
- 1
- Journal Page Range
- p. 53-65.
- ISSN
- 0992-4361
- CODEN
- EJSCE5
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 27067693
- Subject category
- S36: MATERIALS SCIENCE; S36: MATERIALS SCIENCE; S36: MATERIALS SCIENCE;
- Descriptors DEI
- ABSORPTION SPECTROSCOPY; CRYSTAL STRUCTURE; ELECTRIC CONDUCTIVITY; ELECTRON DIFFRACTION; ELECTRONIC STRUCTURE; EMISSION SPECTROSCOPY; HIGH-TC SUPERCONDUCTORS; LITHIUM COMPOUNDS; NIOBIUM COMPOUNDS; SODIUM COMPOUNDS; SYNTHESIS; TRANSITION TEMPERATURE; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION
- Descriptors DEC
- ALKALI METAL COMPOUNDS; COHERENT SCATTERING; DIFFRACTION; ELECTRICAL PROPERTIES; ELECTRON MICROSCOPY; MICROSCOPY; PHYSICAL PROPERTIES; SCATTERING; SPECTROSCOPY; SUPERCONDUCTORS; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPOUNDS