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Partial Anion Exchange in Ag 23 Te 12 X : The Solid Solutions Ag 23 Te 12 Cl 1– x Br x , Ag 23 Te 12 Br 1– y I y and Ag 23 Te 12 Cl 1– z I z
Author(s) -
Osters Oliver,
Nilges Tom
Publication year - 2010
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.200900294
Subject(s) - tetragonal crystal system , solid solution , orthorhombic crystal system , bromine , lattice constant , crystallography , crystal structure , stoichiometry , ternary operation , powder diffraction , analytical chemistry (journal) , neutron diffraction , materials science , x ray crystallography , thermal decomposition , diffraction , chemistry , programming language , physics , organic chemistry , chromatography , computer science , optics , metallurgy
X‐ray powder diffraction, EDX and DSC measurements were performed in order to determine the structural and thermal properties of the solid solutions of Ag 23 Te 12 Cl 1– x Br x , Ag 23 Te 12 Br 1– y I y and Ag 23 Te 12 Cl 1– z I z . A complete solid solution exists between the two ternary end members Ag 23 Te 12 Cl and Ag 23 Te 12 Br, whereas the substitution of bromine by iodine can only be observed up to y = 0.3 in Ag 23 Te 12 Br 1– y I y under thermodynamically controlled synthesis conditions. Even chlorine can be partially substituted by small amounts of iodine up to a certain extend. Temperature dependent single crystal structure determinations of crystals with the nominal composition Ag 23 Te 12 Cl 0.95 I 0.05 substantiated the significant influence of the iodine intake on the lattice parameters of the pseudo‐tetragonal orthorhombic system, especially at low temperatures. A systematic deviation from the 1:1 ratio of the a and b lattice parameter (pseudo‐tetragonal ratio) was observed upon cooling, which could not be detected in the case of the ternary compounds. X‐ray powder diffraction experiments gave a first hint on the non‐stoichiometry of this set of materials and all compounds show peritectic decomposition to binary phases at temperatures slightly above 680 K.