Heyns, Anton M. and Prinsloo, Linda C. and Range, Klaus-Jürgen and Stassen, Martin (1998) The vibrational spectra and decomposition of alpha-calcium nitride (alpha-Ca3N2) and magnesium nitride (Mg3N2). JOURNAL OF SOLID STATE CHEMISTRY, 137 (1). pp. 33-41. ISSN 0022-4596, 1095-726X
Full text not available from this repository.Abstract
alpha-Ca3N2 has been characterized by X-ray powder diffraction and its structure confirmed by a crystal structure refinement with the Rietveld method. Ca3N2 and the isostructural Mg3N2 crystallize in the anti-bixbyite structure of the mineral (Mn, Fe)(2)O-3 in the body-centered space group of Ia3(T-h(7)), and the general appearance of their infrared and Raman spectra resembles that of the sesquioxides belonging to the same space group. The decomposition of M3N2 (M = alpha-Ca, Mg) into M(OH)(2) and NH3, when exposed to the atmosphere, is reported. The presence of NH4+ vibrational bands in the decomposition products is explained in terms of the existence of Bronsted acid centers on the surface of the solid. During the initial stages of decomposition, infrared bands characteristic of adsorbed NH3 were observed, showing that Lewis centers also exist on the surface. The decomposition product Mg(OH)(2) has weaker proton-donating centers than Ca(OH)(2). The kinetics of the decomposition of Mg3N2, which is a much slower reaction than that of alpha-Ca3N2, has been studied with FT-IR microspectrometry, and it is shown that the formation of Mg(OH)(2) is a three-dimensional diffusion process while the proton donation by the hydroxide to adsorbed NH3 to form NH4+ ions is a quasi-first-order reaction. (C) 1998 Academic Press.
| Item Type: | Article |
|---|---|
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie > Alumni or Retired Professors > Prof. Dr. Klaus-Jürgen Range |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 24 Feb 2023 11:14 |
| Last Modified: | 24 Feb 2023 11:14 |
| URI: | https://pred.uni-regensburg.de/id/eprint/49982 |
Actions (login required)
 |
View Item |
