Crystal structure of YbMn ∼0.17Si ∼1.83: a new AlB 2–BaAl 4 intergrowth compound

Abstract

We report on the crystal structure of YbMn 0.17Si 1.83, a new type structure based on an intergrowth of three AlB 2 blocks and one BaAl 4 block. In the BaAl 4 block, the manganese atoms occupy one third of the pyramidal sites as observed in many non-stoichiometric CeNiSi 2-type compounds. The inner AlB 2 block is only 2/3 occupied by the silicon atoms as observed in the related Ho 3Si 4 and ErGe 1.83 compounds. Isotypic and related compounds are found in other R–Mn–Si systems (R=Ho–Lu). The structural relationships with other binary and ternary compounds are examined and the common structural features are discussed.