C–Gd2S3 und C–Tb2S3: Darstellung und Röntgenstrukturanalyse von Einkristallen

✍ Scribed by Thomas Schleid; Frank A. Weber

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: German
• Weight: 73 KB
• Volume: 624
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/(sici)1521-3749(199804)624:4<557::aid-zaac557>3.0.co;2-l

✦ Synopsis

Pale yellow, bead-shaped single crystals of C-type Gd 2 S 3 (a = 838.47(9) pm) and Tb 2 S 3 (a = 835.23(9) pm) are obtained upon the oxidation of the respective rare-earth metal (M = Gd and Tb) with sulfur (molar ratio 2 : 3) in evacuated silica tubing at 700 °C in the presence of fluxing CsCl within five days. Their crystal structure belongs to a cation-deficient Th 3 P 4 -type variant (cubic, I43d) according to M 2.667 & 0.333 S 4 (Z = 4) or M 2 S 3 (Z = 5.333) offering coordination numbers of eight (S 2± arranged as trigonal dodeca-hedra) to the cations. In spite of the high Cs + activity in molten CsCl, no cesium incorporation into the M 5.333 & 0.667 S 8frame structure (e. g. as CsM 5 S 8 with Z = 2) can be achieved, judged from refined occupation factors of M 3+ very close to x = 8/9 for M 3x S 4 .