Syntheses and crystal structures of trigonal rare-earth dioxymonocyanamides, Ln{sub 2}O{sub 2}CN{sub 2} (Ln=Ce,Pr,Nd,Sm,Eu,Gd)
- Osaka Univ. (Japan)
New compounds, trigonal rare-earth dioxymonocyanamides Ln{sub 2}O{sub 2}CN{sub 2}, were synthesized by heating Ln{sub 2}O{sub 3} (Ln = Nd,Sm,Eu,Gd), Ce{sub 2}(CO{sub 3}){sub 3} {center_dot} 8H{sub 2}O, or Pr{sub 6}O{sub 11} in the presence of carbon underflowing ammonia gas. The crystal structures of Ln{sub 2}O{sub 2}CN{sub 2} were refined by the Rietveld method using X-ray diffraction data. The Ln{sub 2}O{sub 2}CN{sub 2} compounds crystallize in the trigonal space group P3m1, with a and c parameters varying from 3.9442 to 3.7812 {angstrom} and from 8.3609 to 8.2311 {angstrom}, respectively, as Ln atoms change from Ce to Gd. A choice of the space group was done assuming that the structure of Ln{sub 2}O{sub 2}CN{sub 2} is like that of Ln{sub 2}O{sub 2}S. In this paper, structural parameters for both Ce{sub 2}O{sub 2}CN{sub 2} and Gd{sub 2}O{sub 2}CN{sub 2} are not reported because the parameters for the atoms did not converge to reasonable values. These compounds have the layer structures which consist of the Ln{sub 2}O{sub 2}{sup 2+} layers with the interlayer CN{sub 2}{sup 2{minus}} ions. The Ln{sub 2}O{sub 2}{sup 2+} layers are piled perpendicular to the c axis and the linear cyanamide ions, {sup {minus}}N=C=N{sup {minus}}, are inserted parallel to the c axis.
- OSTI ID:
- 450701
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 125; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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