Synthesis and Structure Approach of K3Ba7Al6F33Cl2

✍ Scribed by A. Le Bail; A. Hemon-Ribaud; G. Courbion

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 418 KB
• Volume: 107
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1343

✦ Synopsis

An approach of the structure of (\mathrm{K}{3} \mathrm{Ba}{7} \mathrm{Al}{6} \mathrm{~F}{33} \mathrm{Cl}{2}) is performed despite many defects: systematic twinning, partial order of the (\mathrm{K}) and Ba atoms at the same sites, and correlated orientational disorder of some (\left|\mathrm{AIF}{6}\right|) octahedra. The structure is refined to (R_{F}=0.031) in the (P \overline{3} \mathrm{~m} \mid) space group from 1500 unique reflections merged in the (6 / \mathrm{mmm}) Laue symmetry (two equal volume domains with overlapping (h k l) and (h \bar{h} \bar{T}) reflections): (Z=3 ; a=18.863(4) \AA_{1} c=7.636(2) \AA \AA). It is built up from isolated dimeric (\left[\mathrm{Al}{2} \mathrm{~F}{11}\right]) groups of corner-sharing (\left{\mathrm{AlF}{6}\right]) octahedra. The (\mathrm{Cl}) atoms are octahedrally coordinated by the (\mathrm{Ba}) and (\mathrm{K}) cations, forming infinite chains of face-sharing (\left[\mathrm{C}(\mathrm{Ba}, \mathrm{K}){6}\right]) octahedra, parallel to ([001}). 1993 Academic Press. Inc.