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Pr 10 [Si 10−x Al x O 9+x N 17−x ]Cl with x ≈ 1 – an Oxonitridoaluminosilicate Chloride
Author(s) -
Lieb Alexandra,
Lauterbach Rainer,
Schnick Wolfgang
Publication year - 2006
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200500368
Subject(s) - crystallography , crystal structure , electron microprobe , praseodymium , chloride , x ray crystallography , analytical chemistry (journal) , chemistry , materials science , inorganic chemistry , diffraction , mineralogy , physics , organic chemistry , chromatography , optics
The oxonitridoaluminosilicate chloride Pr 10 [Si 10−x Al x O 9+x N 17−x ]Cl was obtained by the reaction of praseodymium metal, the respective chloride, AlN and Al(OH) 3 with “Si(NH) 2 ” in a radiofrequency furnace at temperatures around 1900 °C. The crystal structure was determined by single‐crystal X‐ray diffraction ( Pbam , no. 55, Z = 2, a = 10.5973(8) Å, b = 11.1687(6) Å, c = 11.6179(7) Å, R 1 = 0.0337). The sialon crystallizes isotypically to the oxonitridosilicate halides Ce 10 [Si 10 O 9 N 17 ]Br, Nd 10 [Si 10 O 9 N 17 ]Br and Nd 10 [Si 10 O 9 N 17 ]Cl, which represent a new layered structure type. The structure refinement was performed utilizing an O/N‐distribution model according to Paulings rules, i.e. nitrogen was positioned on all bridging sites and mixed O/Noccupation was assumed on the terminal sites resulting in charge neutrality of the compounds. The Si and Al atoms were refined equally distributed on their three crystallographic sites, due to their poor distinguishability by X‐ray analysis. The tetrahedra layers of the structure consist of condensed [(Si,Al)N 2 (O,N) 2 ] and [(Si,Al)N 3 (O,N)] tetrahedra of Q 2 and Q 3 type. The chemical composition of the compound was derived from electron probe micro analyses (EPMA).