Herbert Boller

Ternäre Thallium-Übergangsmetall-Chalkogenide mit ThCr2Si2-Struktur

The existence of ternary chalcogenides of general composition TlT2X2 (T=Fe,Co,Ni,X=S;T=Fe,Co,Ni,Cu,X=Se) crystallizing in the ThCr2Si2-structure type has been established. The crystal structure of TlCo2S2 was refined from single crystal diffractometer data. The dimensions of the tetragonal unit cells are: TlFe2S2;a=3.755 (1),c=13.35 (1) Å; TlCo2S2:a= =3.7410 (5),c=12.956(5) Å; TlNi2S2:a=3.792 (1),c=12.77 (1) Å; TlFe2Se2:a=3.890 (1),c=14.00(1) Å; TlCo2Se2:a=3.847 (1),c=13.54 (1) Å; TlNi2Se2:a=3.866 (1),c=13.41 (1) Å; TlCu2Se2:a=3.852 (1),c=14.01 (1) Å. These phases are the first chalcogenides found to crystallize in the ThCr2Si2-structure type. Unlike the already known representatives of this structure type they show a pronounced partial ionic character. Interatomic distances as well as the relations to the alkali thiometallates of Co and Mn are discussed.The existence of ternary chalcogenides of general composition TlT 2 X 2 (T=Fe,Co,Ni,X=S;T=Fe,Co,Ni,Cu,X=Se) crystallizing in the ThCr2Si2-structure type has been established. The crystal structure of TlCo2S2 was refined from single crystal diffractometer data. The dimensions of the tetragonal unit cells are: TlFe2S2;a=3.755 (1),c=13.35 (1) A; TlCo2S2:a= =3.7410 (5),c=12.956(5) A; TlNi2S2:a=3.792 (1),c=12.77 (1) A; TlFe2Se2:a=3.890 (1),c=14.00(1) A; TlCo2Se2:a=3.847 (1),c=13.54 (1) A; TlNi2Se2:a=3.866 (1),c=13.41 (1) A; TlCu2Se2:a=3.852 (1),c=14.01 (1) A. These phases are the first chalcogenides found to crystallize in the ThCr2Si2-structure type. Unlike the already known representatives of this structure type they show a pronounced partial ionic character. Interatomic distances as well as the relations to the alkali thiometallates of Co and Mn are discussed.

Channel structures based on octahedral frameworks: The crystal structure of TlTi5Se8, TlV5Se8, and TlCr5Se8 and its relationships to TlCr3S5, hollandites, and psilomelane

Abstract Tlti 5 Se 8 , TlV 5 Se 8 , and TlCr 5 Se 8 are monoclinic, space group C2 m , Z = 2 , TlV 5 S 8 type with lattice parameters a = 18.773(2), b = 3.5834(1), c = 9.1065(7) A , β = 104.13(1) ° ( TlTi 5 Se 8 ) a = 18.354(1), b = 3.4656(1), c = 8.9036(3) A , β = 104.03(1) ° ( TlV 5 Se 8 ) a = 18.699(1), b = 3.5942(1), c = 8.9418(9) A , β = 104.70(1) ° ( TCr 5 Se 8 ) A unified scheme is developed for the TlV 5 S 8 , TlCr 3 S 5 , hollandite, and psilomelane structures on the basis of ideal close packing.

Neue Verbindungen mit KCu4S3-Struktur

TlCu4S3, TlCu4Se3, KCu4Se3, RbCu4Se3, CsCu4S3 and CsCu4Se3 were prepared by direct synthesis or by the carbonate melt method. They are isotypic with KCu4S3, space group P4/mmm,Z=1. The lattice parameters are: TlCu4S3:a=3.894(1)Å,c=9.33(1)Å, TlCu4Se3:a=3.974(4)Å,c=9.84(2)Å, KCu4Se3:a=3.963(4)Å,c=9.81(3)Å, RbCu4Se3:a=4.048(2)Å,c=9.86(1)Å, CsCu4S3:a=3.964(3)Å,c=9.67(1)Å,and CsCu4Se3:a=4.091(2)Å,c=10.08(1)Å. The crystal structure of TlCu4S3 was refined from single crystal diffractometer data. Isotypy of the other compounds was checked by visual inspection of rotating crystal orDebye Scherrer film intensities. The relationship between the crystal structures of the MCu4X3-phases, the TlT2X2-phases (ThCr2Si2 type) and the anti-CaF2 type is shown.

Die Kristallstrukturen von Ta2S2C und Ti4S5 (Ti0,81S)

ZusammenfassungEin durch Sintern hergestelltes Komplexcarbid der Formel Ta2S2C läßt sich durch mechanisches Verreiben in eine Form überführen, die ein besonders einfaches Bauprinzip aufweist. Diese Verbindung (1s-Ta2S2C) hat die Gitterparameter:a=3,265,c=8,537 Å undc/a=2,615. Die Atomparameter sind: 2 Ta in 2 d) (z=0,141), 2 S in 2 d) (z=0,65) und C in 1 a) der Raumgruppe

Alloy phases crystallizing with structures which occur with non-metallic compounds

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Na3Fe2S4, ein Thioferrat mit gemischt valenter sk∞/1[FeS2]-Kette

.Ein Strukturvorschlag für die bei hoher Temperatur stabile Phase 3s-Ta2S2C mit den Gitterparametern:aH=3,276,cH=25,62 Å undc/a=7,82, Raumgruppe

Die Kristallstruktur von TlFeSe2 und TlFeS2

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