Structural determination of physical properties in cuprates

Recently, the crystal structure of synthetic and natural Cu-O compounds was analyzed in the unified classification scheme. Structural units of cuprates as salts of hypothetical copper acids were distinguished and assumed to be responsible for characteristic physical properties of these Cu-O compounds. In this work the optical and magnetic properties were studied in a series of synthetic and natural cuprates. The fine structure in the optical spectra of (M₂Cu₂O₃)_m(CuO₂)_n, CuGeO₃, linarite PbCu(OH)₂(SO₄) and malachite Cu₂(OH)₂CO₃ and other Cu-O compounds was correlated to the electronic excitations in particular structural units typical of cuprates. The temperature dependence of magnetic susceptibility was investigated on a series of Cu oxysalt minerals. The dimerization of magnetic moments was considered as a property, which was determined by the type of cuprate structural units. The observed relationship between the crystal structure and physical properties is useful in search of new magnetic materials.