Ce₆ZnBi₁₄ and Pr₆InSb₁₅: Ternary rare-earth intermetallics with extended pnicogen ribbons

Chem. Met. Alloys 1 (2008) 76-83

https://doi.org/10.30970/cma1.0008

Andriy V. TKACHUK, Thomas TAM, Arthur MAR

The ternary rare-earth pnictides Ce₆ZnBi₁₄ and Pr₆InSb₁₅ have been prepared by reaction of the elements at 950 °C. Their crystal structures were determined by single-crystal X-ray diffraction (Ce₆ZnBi₁₄, Pearson symbol oI42, orthorhombic, space group Immm, Z = 2, a = 4.3916(4) Å, b = 15.399(1) Å, c = 19.315(2) Å; Pr₆InSb₁₅, Pearson symbol oI44, orthorhombic, space group Immm, Z = 2, a = 4.2373(3) Å, b = 15.037(1), c = 19.337(1) Å). Ce₆ZnBi₁₄ and Pr₆InSb₁₅ can be considered to be stuffed variants of the (U_0.5Ho_0.5)₃Sb₇ and La₆MnSb₁₅ structure types, respectively, in which square pyramidal sites are partially occupied by Zn or In atoms. All of these compounds are characterized by extensive homoatomic bonding of the pnicogen (Sb or Bi) atoms within the anionic substructure.

Structure of Ce₆ZnBi₁₄ and Pr₆InSb₁₅ viewed down the a direction.

Keywords

Pnictide / Intermetallics / Crystal structure