Wang Jian, Owens-Baird Bryan, Kovnir Kirill
Department of Chemistry and Biochemistry, Wichita State University, Wichita, Kansas 67260, United States.
Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States.
Inorg Chem. 2022 Jan 10;61(1):533-541. doi: 10.1021/acs.inorgchem.1c03217. Epub 2021 Dec 14.
Three new antimonide Zintl phases, RbGaSb, CsGaSb, and CsInSb, were discovered during exploration of corresponding A-M-Sb (A = Rb, Cs; M = Ga, In) ternary systems while searching for new clathrates. The AGaSb phases crystallize in the tetragonal space group 4/ (No. 137) in the LiBS structure type, while CsInSb crystallizes in lower symmetry in the orthorhombic space group (No. 64) in the KGaSb structure type with additional disorder of one of the Cs sites. The crystal structures of all three reported AMSb compounds are composed of two-dimensional [MSb] tetrahedral layers separated by Rb or Cs cations. [MSb] layers are built from fused M-Sb pentagons and hexagons, which are also the main structural units for AMSb clathrate cages. The semiconductor nature of AMSb was suggested by band structure calculations and confirmed by transport property characterization. CsGaSb is a rare example of an n-type pnictide Zintl phase. All reported compounds exhibit low thermal conductivity typical for complex antimonides of heavy elements.
