Synthesis, Structure, and Electrical Properties of Ta₄FeTe₄

Abstract

Ta,FeTe, has been synthesized and its structure determined by single-crystal X-ray methods. It crystallizes in the orthorhombic space group Pbam wi !h Z = 4 and a = 10.514(5), b = 18.2?5(?), and c = 4.815(1) A. Ta4FeTe, has a chain structure built up by Fe-centered Ta8-square antiprisms sharing common square faces. The resistivity of Ta4FeTe4 has been measured by a two-point method. Ta,FeTe, shows metallic behavior. The structure of Ta4FeTe4 is discussed in relation to other early transition metal cluster compounds. A rational approach to the synthesis of related compounds is proposed.

New Ternary Lanthanide Transition-Metal Tellurides: Dy6MTe2, M=Fe, Co, Ni

“…The stability can usually be attributed to strong bonding between the interstitial, often a late transition metal, and a surrounding host metal from an early metal group, a circumstance that is another reminder of some early ideas of Brewer (1). Among the many reduced chalcogenides of the early transition metals that demonstrate these heterometal features are Ta M S (2, 3), Ta M Se (4), Ta MSe (5), Nb MS (6), Hf MTe (7), all with some combination of M"Fe, Co, Ni, Zr MTe (M"Mn, Fe, Co, Ni, Ru, Pt) (8), Hf MTe (9) (M"Mn}Fe), Nb Ni \V S >V (6), Ta MTe (M"Cr, Fe}Ni, Al, Si) (10,11), Sc Ni Te (12), Y M Te (M"Fe}Ni) (13), and Sc MTe (14) (M"Mn}Ni). Many of these phases also have a common structural motif, have tricapped trigonal prismatic clusters of the more active metal that share basal faces, and are centered by the late transition metal.…”

Synthese, Struktur und Eigenschaften der tantalreichen Silicidchalkogenide Ta15Si2QxTe10x (Q = S, Se)

“…Die Silicidchalkogenide Ta 15 [24]). Aus der spezifischen Orientierung beider Ta 9 Si-Tetrakaidekaeder zueinander ergibt sich fu È r Ta1 eine verzerrt kubische Koordination von acht Ta-Atomen.…”

“…Geburtstag gewidmet Inhaltsu È bersicht. Die quaterna Èren Tantalsilicidchalkogenide Ta 15 Si 2 Q x Te 10±x (Q = S, Se) sind durch Umsetzung entsprechender Gemenge aus Dichalkogeniden, Silicium und Tantal bei 1770 K in zugeschweiûten Molybda Èntiegeln herstellbar. Ihre Struktur wurde aus den intensita È tssta Èrksten Reflexen von ca.…”

“…Synthesis, Structure, and Properties of the Tantalum-rich Silicide Chalcogenides Ta 15 Si 2 Q x Te 10±x (Q = S, Se).…”

“…The quaternary tantalum silicide chalcogenides Ta 15 Si 2 Q x Te 10±x (Q = S, Se) are accessible from proper, compacted mixtures of the respective dichalcogenides, silicon and elemental tantalum at 1770 K in sealed molybdenum tubes. The structures were determined from the strongest Xray intensities of fibrous crystals with cross sections of about 3 lm and confirmed by fitting the profile of single phase Xray diffractograms.…”