Inorganic Chemistry, Vol.34, No.22, 5524-5529, 1995
Main-Group Element Size and Substitution Effects on the Structural Dimensionality of Zirconium Tellurides of the Zrsis Type
Chemical and structural variations in compounds related to the layered compound ZrSiTe have been examined. A study of ZrSi1-xGexTe solid solutions show that the Si:Ge ratio can be varied in any stoichiometric proportion with the result that increasing atomic size (increasing x) affects both the shrinkage of the c axis and the expansion of the a axis. Expansion of the a axis results in relief of steric crowding within and between Te layers that permits increased bonding between Zr and Te in adjacent layers, This steric-electronic synergy is discussed, A new member of this structural family, ZnSnTe, was synthesized (space group P4/nmm, No, 129, Z = 2, a = 4.0549(6) Angstrom, c = 8.711(2) Angstrom). ZrSnTe has a fully three-dimensional structure; bond distances of Zr to the intralayer and interlayer Te, 3.038 and 3.084 Angstrom, respectively, are almost equal, Four new pseudoternary tellurides are reported. Two of pseudoternary tellurides, ZrSi0.66As0.34Te and ZrSi0.5As0.7Te0.8, were refined in the same space group with lattice parameters a = 3.8116(1) Angstrom, c = 8.398(3) Angstrom for ZrSi0.5As0.7Te0.8 and a = 3.7110(3) Angstrom, c = 9.723(2) Angstrom for ZrSi0.66As0.34Te ZrSi0.66As0.34Te, isostructural with ZrSiTe, has a c axis length 0.22 Angstrom larger than that of ZrSiTe; arsenic in this material substitutes solely for silicon, The isotypic ZrSi0.5As0.7Te0.8 exhibits substitution for both Si and Te and can be formulated as Zr(Si0.5As0.5)(As0.2Te0.8). Four-probe resistivity measurements (77-300 K) show all ternary and pseudoternary tellurides to be metallic with resistivities of similar to 10(-4) Omega cm.
Keywords:METAL