Zr7(Sb,Se)4 – eine polare Variante des Nb7P4-Strukturtyps
✍ Scribed by H. Kleinke; B. Harbrecht
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- German
- Weight
- 164 KB
- Volume
- 625
- Category
- Article
- ISSN
- 0372-7874
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✦ Synopsis
Struktur aus, die kondensierte, dreifach u È berdachte trigonal prismatische Zr 9 -Cluster, stabilisiert durch interstitielle Sb/ Se-Atome, entha È lt. Die verbleibenden Sb-und Se-Atome befinden sich statistisch verteilt in einfach und zweifach u È berdachten trigonal prismatischen Zr 7 -und Zr 8 -Clustern. Die charakteristischen strukturellen Gemeinsamkeiten und Unterschiede zwischen Zr 7 (Sb,Se) 4 und Zr 7 P 4 werden hervorgehoben.
Zr 7 (Sb,Se) 4 ± a Polar Variant of the Nb 7 P 4 Structure Type Abstract. Single crystals of Zr 7 Sb 1.6(1) Se 2,4 were obtained by arc-melting of compressed mixtures of Zr, ZrSb 2 , and ZrSe 2 , followed by annealing at 1300 °C in an induction furnace using traces of iodine to promote crystal growth. The crystal structure (a = 375.98(4), b = 1662.6(2), c = 1476.7(2) pm, V = 923.1(2) 10 6 pm 3 , Cmc2 1 , Z = 4) was determined by single crystal X-ray means. Zr 7 Sb 1.6(1) Se 2.4 forms a unique polar structure composed of condensed tri-capped trigonal prismatic Zr 9 clusters, being stabilized by interstitial Sb/Se atoms. The remaining Sb and Se atoms reside in mono-and bi-capped trigonal prismatic Zr 7 and Zr 8 clusters, respectively, of the extended cluster network. Characteristic structural distinctions and relations between Zr 7 (Sb,Se) 4 and congeneric Zr 7 P 4 are highlighted.