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Crystal Growth, Structure and Properties of the Palladium‐rich Telluride Pd 13 Te 3
Author(s) -
Janetzky Manuel,
Harbrecht Bernd
Publication year - 2006
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200500455
Subject(s) - telluride , crystallography , palladium , crystal structure , tellurium , materials science , lead telluride , single crystal , paramagnetism , chemistry , inorganic chemistry , metallurgy , physics , doping , catalysis , condensed matter physics , biochemistry , optoelectronics
Silver shiny crystals of Pd 13 Te 3 were produced by chemical vapour transport reaction using PdCl 2 or PdBr 2 as transport agent. The crystal structure of Pd 13 Te 3 was established by means of single crystal X‐ray diffraction (space group F ${\rm d}{\bar 3}\rm m$ , cF128, a = 1266.81(6) pm, 15 variables, R 1 (all) = 0.0306). Pd 13 Te 3 is isotypic to Li 13 In 3 [1]. The structure of Pd 13 Te 3 represents a 4a · 4a · 4a ordering variant of a β ‐brass type structure for which the atoms of the minority component are ordered according to the motif of a cubic Laves phase on a length scale of ${{a\sqrt{2}} \over {4}}$ . The structural relations are confirmed by group‐subgroup analyses. Pd 13 Te 3 shows no discernible homogeneity range and coexists with a Te‐saturated fcc solid solution Pd 1− x Te x (x ≈ 0.12) and Pd 20− x Te 7 (x ≈ 0.05). The telluride is noticeably chemically inert. It requires hot aqua regia to get attacked. Pd 13 Te 3 undergoes a peritectoid decomposition at about 1040 K, is weakly paramagnetic (χ ≈ 6·10 −10 m 3 mol −1 related to ${{1} \over {16}} {\rm Pd}_{13}{\rm Te}_{3}$ ) and a moderate metallic conductor (ρ ≈ 2·10 −5 Ωm). Extended Hückel calculations give no hints for an electronic stabilisation of the telluride by the Hume‐Rothery mechanism otherwise effective for brass‐type phases. According to an analysis of crystal orbital overlap populations heteroatomic interactions contribute decisively to the stability of the phase.