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Ca 14 FeAs 11 – A structure comprising structural motifs of iron‐based superconductors and Ca‐As Zintl phases
Author(s) -
Hoffmann Andrea V.,
Fässler Thomas F.,
Hlukhyy Viktor
Publication year - 2022
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.202200168
Subject(s) - crystallography , materials science , intermetallic , structure type , tetrahedron , fermi level , space group , superconductivity , type (biology) , crystal structure , alloy , chemistry , condensed matter physics , x ray crystallography , diffraction , physics , metallurgy , electron , quantum mechanics , optics , ecology , biology
Ca 14 FeAs 11 is the first iron‐containing representative of the Ca 14 AlSb 11 structure type and the first compound with isolated FeAs 4 tetrahedra. It can be regarded as a salt‐like compound containing isolated [FeAs 4 ] 9− tetrahedra, linear [As 3 ] 7− units, isolated As 3− anions and Ca 2+ cations and thus is a borderline compound between binary Fe−As intermetallics and salt‐like calcium arsenides. Ca 14 FeAs 11 is obtained by a two‐step high‐temperature reaction, in which preformed FeAs alloy is heated with Ca in the presence of additional As in a sealed silica tube. Structure determination from single crystals at 150 K reveal the Ca 14 AlSb 11 structure type with space group I 4 1 / acd ( Z =8, a =15.6268(2) Å, c =20.9781(5) Å, and V =5122.79(15) Å 3 ). Band structure calculations predict metallic properties with strong contribution of Fe orbitals to the density of states at the Fermi level.