Crystal structure of the incommensurate modulated composite ruthenate [Ba]1.30[(Ru,Cu)O3]

Abstract

Abstract [Ba]1.30[(Ru,Cu)O3] crystallizes in a modulated composite crystal structure previously observed for [Ba] x [(Pt,Cu)O3], x = 1.317. The composite structure is refined in one centrosymmetric and one non-centrosymmetric model in the superspace groups P-31c(00γ) and P31c(00γ), respectively, with a = 10.135(1) Å, c = 4.2902(3) Å and q = 1.601(1) c *. The centrosymmetric case was refined using Crenel functions. The first substructure is formed by Ba cations located in channels of the second substructure, which consists of one-dimensional chains of face-sharing polyhedra ∞ 1[O3/2(Ru,Cu)O3/2]: alternating blocks of mostly three octahedra and trigonal prisms. DC-susceptibility measurements result in typical spin-glass behavior, an effective magnetic moment of μ eff = 2.55μB, and a Weiss temperature of θ p = -202 K.