Dysprosium substitution in-Bi-based 2223 materials: the role of the superconducting layer charge distribution for inducing a structural phase transition

摘要

The chemical synthesis of dysprosium doped Bi-based 2223 high-T{sub}c superconducting materials prepared by either a "two-powder process" or a "crystalline-glassy matrix precursor" method has been examined. In both cases, the 2223 phase is seen to be unstable. The reason for the Dy-doped 2223 instability is discussed and found to originate in electronically mediated bond-mismatch, resulting in a strain energy minimization by phase decomposition.