Microcomposites based on superconducting cuprates

Chemical aspects of the formation of microcomposites based on superconducting cuprates are considered. The materials are composed of a superconducting ceramic matrix and micro- or nanoinclusions of the non-superconducting phase, which are uniformly distributed in the matrix. Requirements on the operating characteristics of the superconducting ceramics are described and routes to high critical current densites are outlined. Phase equilibria in the generic systems are considered. Physical and chemical criteria for the choice of phases that can form non-superconducting inclusions are proposed. Methods of preparation and the microstructures and superconducting properties of the composites based on cuprates RBa₂Cu₃O_7–δ (R is the rare-earth element) and on Bi₂Sr₂CaCu₂O_8+δ and (Bi,Pb)₂Sr₂Ca₂Cu₃O_10+δ are considered.