Synthesis and crystal structure of K2NiF4-type novel Gd1+xCa1-xAlO4-xNx oxynitrides

JOURNAL OF ALLOYS AND COMPOUNDS

卷:582

Article

Masubuchi, Yuji¹  Hata, Tomoyuki¹  Motohashi, Teruki¹  Kikkawa, Shinichi¹ 

[1] Hokkaido Univ, Fac Engn, Kita Ku, Sapporo, Hokkaido 0608628, Japan

关键词: Inorganic materials;    Rare earth alloys and compounds;    Solid state reactions;    Crystal structure;    Synchrotron radiation;    X-ray diffraction;   

DOI  :  10.1016/j.jallcom.2013.08.140

来源: Elsevier

【 摘 要 】

Novel gadolinium calcium aluminum oxynitrides, Gd1+xCa1-xAlO4-xNx, were prepared in x = 0.15-0.25 by the solid state reaction of a nitrogen-rich mixture with AlN as an aluminum source; the mixture was sintered twice at 1500 degrees C for 5 h under 0.5 MPa of nitrogen gas. Shift in the optical absorption edge was observed in their diffuse reflectance spectra from 4.46 eV for the oxide (x = 0) to 2.94 eV for the oxynitride at x = 0.2. The crystal structure of Gd1.2Ca0.8AlO3.8N0.2 at x = 0.2 was refined using a synchrotron X-ray diffraction data as a layered K2NiF4-type structure with the I4mm space group. Longer Al-O/N bond lengths in the oxynitride than those in GdCaAlO4 suggest that the nitride ions are in the apical site of aluminum polyhedron, similar to those in Nd2AlO3N. (c) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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