Search

The results of studies of halogen-containing yttrium-barium cuprates are reviewed. Different methods for the synthesis of YBa 2 Cu 3 O 7− x Hal y phases are discussed and the structural features and physical properties of the phases are analysed. Attention is given mainly to the low-temperature methods which allow preparation of single-phase samples. Mechanisms of halogen insertion into the YBa 2 Cu 3 O 7− x lattice are discussed, as well as the role of different structural fragments in the high-temperature superconductivity phenomenon.