The single crystal structure determination of Ln6MnSb15 (Ln=La, Ce), Ln6Mn1−xZnxSb15 (x~0.5), and Ln6ZnSb15 (Ln=La–Pr)

Abstract

Abstract Single crystals of Ln6MnSb15 (Ln=La, Ce), Ln6Mn1−xZnxSb15 (x~0.5), and Ln6ZnSb15 (Ln=La–Pr) have been successfully grown and the compounds adopt the orthorhombic La6MnSb15 structure type (space group Immm), with a~4.3 Å, b~15 Å, and c~19 Å. This structure is comprised of antimony nets and antimony ribbons which exhibit positional disorder at connecting points between antimony substructures, in addition to two partially occupied transition metal sites. The unit cell volumes of the La analogs displayed a systematic decrease upon Zn substitution. However, for the Ce6Mn1−xZnxSb15 and Pr6Mn1−xZnxSb15 (x~0.5), the volumes deviate from linearity as observed in the parent compounds.