Abstract
Polycrystalline vanadium oxynitrides have been prepared by heat-treating V2O5 at high temperature in a flowing ammonia atmosphere. Single-phase cubic samples, with the rock salt structure, were produced by nitridation at 600-700°C. Powder diffraction data from neutrons at two wavelengths and CuΚα X-rays of these oxynitrides were analyzed using the Rietveld method, but strong correlation among the atomic displacement parameters, site occupancies, and the N/O ratio did not allow a refinement of unique compositions. Measured densities and cell volumes were used to limit the possible compositional space for each sample, and these were further limited by the charge neutrality requirement. The electrical resistivity of the single-phase sample is about 2 × 10-3 Ω · cm and is weakly temperature dependent below room temperature. Magnetic susceptibility measurements show no evidence of magnetic ordering and yield a magnetic moment of 0.25 μB per V atom. Electrochemical lithium intercalation measurements indicate that only a small concentration of lithium ions were inserted into the cathode due to the close-packed NaCl structure of cubic vanadium Oxynitride.
| Original language | English |
|---|---|
| Pages (from-to) | 376-383 |
| Number of pages | 8 |
| Journal | Journal of Solid State Chemistry |
| Volume | 122 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 1996 |
Funding
The authors thank Dr. N. J. Dudney for her critical reading of the manuscript, Dr. R. A. Zuhr for the RBS measurement, and Mr. C. F. Luck for his help in fabricating the thin film solid electrolyte cell for the electrochemical measurement. This research was sponsored by the Division of Materials Sciences, U. S. Department of Energy under contract No. DE-AC05-84OR21400 with Lockheed-Martin Marietta Energy Systems. BW was supported by an appointment to the Oak Ridge National Laboratory Postdoctoral Research Program administered by the Oak Ridge Institute for Science and Education.