Zr6STe2 - ein zirconiumreiches Sulfidtellurid mit einer Zr3Te-Teilstruktur vom Re3B-Typ

Abstract

Professor Kurt Dehnicke zum 70. Geburtstag gewidmet Inhaltsu È bersicht. Zr 6 STe 2 ist durch Reduktion eines Gemenges von ZrTe 2 und ZrS 2 mit Zirconium in gasdicht verschweiûten Tantaltiegeln bei 1520 K zuga È nglich. Die ra Èumlich gemittelte Kristallstruktur von Zr 6 STe 2 la È sst sich in der orthorhombischen Raumgruppe Cmcm beschreiben: a = 377.81(4), b = 1156.4(1), c = 887.96(8), Z = 2, Pearson-Symbol oC18, 320 Reflexe (I > 2r(I)), 22 Variablen, R w (I) = 0.088. Zr 6 STe 2 bildet einen eigenen Strukturtyp, der sich struktursystematisch als teilweise aufgefu È llter Re 3 B-Typ einordnen la È sst. Die Telluratome sind dreifach-u È berdacht, verzerrt trigonal-prismatisch von neun Zirconiumatomen umgeben. Die Zr 9 Te-Tetrakaidekaeder sind u È ber gemeinsame trigonale Prismenfla È chen (la È ngs [100]), Kanten (etwa parallel [001]) und Spitzen (la È ngs [010]) zu einem dreidimensionalen Tetrakaidekaedernetzwerk 3 1 [Zr 9/3 Te] verknu È pft, zu dessen Stabilita È t homonukleare Zr±Zr-Bindungswechselwirkungen maûgeblich beitragen. Zwischen den Tetrakaidekaedern befinden sich Zr 6 -Oktaeder, die u È ber Kanten (la È ngs [100]) und Spitzen (la È ngs [001]) zu Schichten verknu È pft sind. Infolge einer Verzerrung der Struktur weitet sich die Ha È lfte der Oktaeder einer Schicht soweit auf, dass die Schwefelatome Platz darin finden. Den Beugungsbefunden nach erfolgt die Ausordnung der Leerstellen in benachbarten Oktaederschichten unabha È ngig voneinander.Abstract. Zr 6 STe 2 is accessible through the reduction of a mixture of ZrTe 2 and ZrS 2 with zirconium in fused tantalum tubes at 1520 K. The spatially averaged crystal structure of Zr 6 STe 2 is described in the space group Cmcm, a = 377.81(4), b = 1156.4(1), c = 887.96(8), Z = 2, Pearson symbol oC18, 320 reflexions (I > 2r(I)), 22 variables, R w (I) = 0.088. Zr 6 STe 2 crystallizes in a unique structure type, which can be seen as a filled Re 3 B type structure. The tellurium atoms are surrounded by nine zirconium atoms situated at the vertices of a distorted, tricapped trigonal prism. The Zr 9 Te tetrakaidecahedra are connected by common triangular prism faces parallel [100], edges approximately along [001] and common vertices along [010], thus forming a three-dimensional tetra-kaidecahedral network 3 1 [Zr 9/3 Te], which is decisively stabilized by homonuclear Zr±Zr-interactions. The tetrakaidecahedra are arranged in such a way, that Zr 6 octahedra occur. The octahedra are arranged into layers by sharing edges parallel [100] and vertices along [001]. As a result of a distortion of the structure, every second octahedron is expanded to such an extent as to be able to smoothly accommodate sulfur atoms. According to the modulation of the diffraction intensities, the vacancy ordering in adjacent layers of octahedra occurs independently of each other.

Planar Nets of Ti Atoms Comprising Squares and Rhombs in the New Binary Antimonide Ti2Sb

“…Thus far, the usability of this map was demonstrated in the subsequent uncoveries of new members of this M 2 Q family, namely Zr 1 -δ Ti 1+ δ As, Zr 1 -δ V 1+ δ As, and HfMQ with M = Ti, V; Q = P, As . Recently, the first example of a new type in this M 2 Q family was detected, namely Zr 2 S 0.33 Te 0.67 . Its <C. N.(Q)> value is indeed eight, as rationalized by calculating its f value.…”

“…31 Recently, the first example of a new type in this M 2 Q family was detected, namely Zr 2 S 0.33 Te 0.67 . 49 Its <C. N.(Q)> value is indeed eight, as rationalized by calculating its f value. Further, an extension to other stoichiometries is possible, as demonstrated by us for the M 5 Q 3 compounds.…”

New Barium Copper Chalcogenides Synthesized Using Two Different Chalcogen Atoms: Ba2Cu6–xSTe4 and Ba2Cu6–xSeyTe5–y

“…That no mixed S/Te occupancies were identified in the structure of Ba 2 Cu 6– x STe 4 has its precedence in the structure of Zr 6 STe 2 . Such mixed occupancies are possible, however, as is the case in Ta 6 S 1+ x Te 3– x (with up to 4% S on Te sites and 7% Te on S sites) and Ta 15 Si 2 S x Te 10– x (with one pure S site and four mixed S/Te sites).…”

Crystal Structure and Physical Properties of the New Chalcogenides Ba3Cu17–x(S,Te)11 and Ba3Cu17–x(S,Te)11.5 with Two Different Cu Clusters

“…While no mixed S:Te occupancies were identified in the sulfide-tellurides Ba 2 Cu 6– x STe 4 and Zr 6 STe 2 , each of the four crystals investigated here has at least one mixed S:Te site, with ratios of up to 30:70 and 80:20, respectively. Other examples for mixed S:Te occupancies, while rare, do exist, including Ta 6 S 1+ x Te 3– x (with up to 4% S on Te sites and 7% Te on S sites) and Ta 15 Si 2 S x Te 10– x (with one pure S site and four mixed S:Te sites, albeit with very high standard deviations).…”