Structure and magnetic properties of Eu ₂CaCu ₂O ₆

A new type of cuprate, Eu ₂CaCu ₂O ₆, has been prepared by high-pressure synthesis. The structure has been determined by high-resolution electron microscopy (HREM) and electron diffraction. A starting structure model was constructed using through-focus exit waves reconstructed from a series of HREM images. The exact structure was determined by refinement using electron diffraction single-crystal data and was confirmed by X-ray Rietveld analysis. The structure consists of CuO ₃planes, containing CuO ₄ squares that form separated Cu ₂O ₆ units, thus giving a zero-dimensional structural character. Magnetic measurements indicate antiferromagnetic behavior with magnetic frustration.