The New Ternary Silicide ErCo3Si2

Abstract

The new ternary silicide ErCo3Si2 adopts the ErRh3Si2 structure type (space group Imma, Pearson code oI24, Z = 4, a = 6:950(1), b = 9:020(2), c = 5:230(1) Å, R1 = 0:0565, wR2 = 0:0355, 253 F2 values, 23 variables). It is a deformation derivative of the CeCo3B2 structure type. The coordination of the Er atom shows a normal 20- vertex polyhedron [Er(Si6Co12Er2)]. The two similar coordination polyhedra of Co are a distorted icosahedron [Co(Si4Co4Er4)], and a distorted icosahedron with one capped face [Co(Si4Co5Er4)]. The Si atom is surrounded by the polyhedron [Si(Co6Si2Er3)]