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Structural Features and Physical Properties of In 2 Bi 3 Se 7 I, InBi 2 Se 4 I, and BiSeI
Author(s) -
Rosenthal Tobias,
Döblinger Markus,
Wagatha Peter,
Gold Christian,
Scheidt ErnstWilhelm,
Scherer Wolfgang,
Oeckler Oliver
Publication year - 2011
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.201100277
Subject(s) - electronegativity , bismuth , electrical resistivity and conductivity , alkali metal , valence (chemistry) , halide , crystal structure , crystallography , selenide , chemistry , single crystal , space group , metal , x ray crystallography , materials science , mineralogy , inorganic chemistry , diffraction , selenium , physics , organic chemistry , quantum mechanics , optics
The quaternary compounds In 2 Bi 3 Se 7 I and InBi 2 Se 4 I have been synthesized via gas phase reactions. They decompose above ca. 400 °C, losing iodine and forming binary compounds. Their crystal structures have been solved and refined using single‐crystal X‐ray diffraction data (In 2 Bi 3 Se 7 I: space group Pnma , a = 13.6720(2), b = 4.0893(3), c = 16.7070(2) Å; InBi 2 Se 4 I: space group Pnma , a = 26.6039(14), b = 4.1285(2), c = 13.5031(9) Å). Both compounds show structural features related to those found in alkali metal bismuth chalcogenides known for their good thermoelectric properties such as β‐K 2 Bi 8 Se 13 . All these structures contain rocksalt‐like building blocks as well as CdI 2 ‐like fragments and loosely bound anions (selenide halides) or cations (alkali metal selenides), respectively, located in rather large cavities which suggests the possibility of phonon scattering by rattling. The electrical resistivity of In 2 Bi 3 Se 7 I and InBi 2 Se 4 I conforms to semiconducting behavior.The total thermal conductivity of sintered pellets of In 2 BiSe 4 I exhibits a maximum of 0.7 W · K –1 · m –1 at 22 K. The rather high electrical resistivity of In 2 Bi 3 Se 7 I and In 2 BiSe 4 I is probably a consequence of the different electronegativities of the constituting elements in combination with the balanced valence states. The related compound BiSeI has a lower electrical resistivity and a higher thermal conductivity featuring a maximum of 10.3 W · K –1 · m –1 at 8.2 K; its Seebeck coefficient (S) amounts to –55 μV · K –1 at 295 K.