New quinternary selenides: Syntheses, characterizations, and electronic structure calculations

• Five new quinternary selenides were synthesized and characterized.
• Structural units, [MSe3]∞1 and [M4Se10]∞1 (M=Tt, Pn), construct the one-dimensional structure.
• Calculations of electronic structure confirm site preference of Sr/La sites.

Five quinternary selenides, Sr2.63Y0.37Ge0.63Sb2.37Se8 (I), Sr2.63La0.37Ge0.63Sb2.37Se8 (II), Sr2.71La0.29Sn0.77Bi2.23Se8 (III), Ba2.67La0.33Sn0.67Sb2.33Se8 (IV), and Ba2.67La0.33Sn0.67Bi2.33Se8 (V), were synthesized by solid-state reaction in fused silica tubes. These compounds are isostructural and crystallize in the Sr3GeSb2Se8 structural-type, which belongs to the orthorhombic space group Pnma   (no. 62). Three structural units, [MSe3]∞1, [M4Se10]∞1 (M=Tt, Pn) and M′ (M′=groups II and III element), comprise the entire one-dimensional structure, separated by M′. Measurements of electronic resistivity and diffused reflectance suggest that IV and V have semiconducting properties. Electronic structure calculations confirm the site preferences of Sr/La element discovered by crystal structure refinement.

Quinternary selenides Ae2.67M0.33Tt0.67Pn2.33Se8 (Ae, M, Tt, Pn=Sr/Ba, Y/La, Ge/Sn, Sb/Bi) were synthesized and their site preferences were characterized by single-crystal X-ray diffraction and electronic structure calculation.Figure optionsDownload as PowerPoint slide