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Si‐based Clathrates with Partial Substitution by Zn and Ga: K 8 Zn 3.5 Si 42.5 , Rb 7.9 Zn 3.6 Si 42.4 , and Cs 8– x Ga 8– y Si 38+ y
Author(s) -
Baran Volodymyr,
Fässler Thomas F.
Publication year - 2015
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.201500147
Subject(s) - alkali metal , halide , stoichiometry , electrical resistivity and conductivity , crystallography , materials science , seebeck coefficient , intermetallic , zinc , inorganic chemistry , crystallinity , metal , flux method , atom (system on chip) , thermoelectric effect , analytical chemistry (journal) , single crystal , chemistry , thermal conductivity , metallurgy , physics , organic chemistry , alloy , embedded system , electrical engineering , composite material , thermodynamics , engineering , chromatography , computer science
The clathrate Cs 8– x Ga 8– y Si 38+ y was obtained from a stoichiometric reaction of the elements in an alkali metal halide flux, whereas K 8 Zn 3.5 Si 42.5 and Rb 7.9 Zn 3.6 Si 42.4 were synthesized using a combined alkali metal halide/zinc flux. These methods allow to get virtually single‐phase materials with good crystallinity. The compounds were analyzed and characterized by means of powder and single‐crystal X‐ray diffraction methods. Rather unexpectedly, the substitution of Si by Zn in K 8 Zn 3.5 Si 42.5 and Rb 7.9 Zn 3.6 Si 42.4 also occurs at the atomic site 24k beside the usually observed 6c site, which has not been found before for intermetallic clathrates with alkali metal guest atoms and substitution of the host atom by group 12 elements. The size effect of the guest atoms Rb and Cs on the alkali metal content of Ga‐Si and Zn‐Si clathrates is established. Furthermore, magnetic and transport measurements (electrical resistivity, Seebeck coefficient and thermal conductivity) are reported.