Structure and magnetic properties of Ca1−x−yMgxCu2+yO3 influenced by isoelectronic substitution x Original Research Article

Phases of the composition Ca1−x−yMgxCu2+yO3 have been prepared for the first time. The compounds are isostructural with the known end-members CaCu2O3 and MgCu2O3 showing a two-leg spin-ladder-like connection of copper and oxygen atoms within the Cu2O3-layer. Opposite the spin ladders this layer is folded, which results in a long-range antiferromagnetic ordering of these phases. The Néel temperature can be adapted by variation of x in Ca1−x−yMgxCu2+yO3 between 24 and 80 K. Several structural features, which influence the magnetic ordering, are discussed.