Crystal structure, chemical bonding, and physical properties of layered AIrSn(2) (A=Sr and Ba)

摘要

We report the experimental and theoretical investigation of structure, chemical bonding interactions, and physical properties of new ternary stannides AIrSn(2) (A=Sr and Ba). AIrSn(2) (A=Sr and Ba) crystallizes in the orthorhombic Re3B-type structure with the space group Cmcm (No. 64). According to single-crystal X-ray diffraction results, the structure of AIrSn(2) (A=Sr and Ba) can be considered as a Zintl-type compound with heterogeneous polyanionic [IrSn2](2-) and A(2+). The specific heat down to 1.8K shows no evidence for bulk superconductivity in either SrIrSn2 or BaIrSn2. Electronic structure calculations, especially chemical bonding interactions in SrIrSn2 and BaIrSn2, match well with the observed structural stability and metallic nature.