The crystal structure of Ta6S

The crystal structure of Zr9S2

“…This distance is conside]ably less than distances found in the h. c. p. form of zirconium metal (3.18 and 3-23 •) and is comparable to that found in the high pressure oophase structure of the metal (2.91 A) when quenched to one atmosphere (Jamieson, 1963). Short intermetallic distances have also been found in other zirconium-rich compounds, such as the o--like Zr4A13 (2.70 A) and the D,8,-type ZrsA13 (2.70/~,) as discussed by Edshammar (1962), and other metal-rich sulfides, such as Ta6S (Franzen & Smeggil, 1970), TazS (Franzen & Smeggil, 1969), and the two V3S phases mentioned earlier. In all these cases, the short distances always appear between the apical and the central atoms of Kasper polyhedra.…”

Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

“…The cooled pellet contained two well separated but poorly crystalline phases. Pieces of these two phases were pulverized and a Guinier X-ray powder pattern of the silver colored phase resembled that calculated for a-Ta^S [35] while the Guinier powder pattern of the gold colored phase resembled those calculated for zirconium deficient monosulfides (Zr^.^S) [20]. Further investigation of the Zr-Ta-S system revealed that Zr-rich samples cleanly reacted in the arcmelter without substantial loss of sulfur and appeared to be homogeneous.…”

“…The last class of compounds to be discussed here includes the binary tantalum metal-rich sulfides TagS [34], a-TagS [35], p-TagS [36], and TagSg [37]. The determining structural features of these compounds are the metal chains of facesharing centered pentagonal antiprisms which can also be described as chains of condensed Ta icosahedra where the apical atom of one icosahedron centers the neighboring icosahedron and vice versa.…”

“…TagS [34], a-TagS [35], and p-Ta^S [36] exhibit strongly metal-metal bonded icosahedral tantalum chains with sulfur atoms bridging these chains. Nb^^Sg [12] and Nbi^Sg [13], on the other hand, are based on capped trigonal prismatic coordinations of sulfur and fragments derived from bcc metal.…”

Interstitially stabilized phases in the zirconium-nickel system

“…As it is the strength of this metal-metal bonding that is essential for the formation of these phases, a better criterion is the condition E n(M-M) / E n(M-X) > 1, where n is the Pauling bond order [4], as detemiined by the A number of metal-rich compounds have been discovered in this lab alone. Considering just the binary sulfides of the Group 4 and Group 5 elements, they include TijS [2], TigS^ [5], ZrjS [6], ZrjiSg [6], ZrgSg [7], HfjS [8], NbjjSg [9], Nbi^Sg [10], Ta^S [11], a-Ta^S [12], P-TagS [13].…”