Magnetic irreversibility characteristics of highly unstable superconducting Ba2Ca2Cu3O and its derivative phase
説明
Abstract We have characterized the magnetic irreversibility field, H irr , for an unstable phase with T c =124 K of the Ba–Ca–Cu–O system prepared by means of high-pressure synthesis and also for its derivative phase with T c =78 K obtained through exposing the as-synthesized sample to H 2 O/N 2 gas. The former phase is of the 0223 structure having a relatively thin “blocking” block consisting of only two BaO layers in between two superconductive Ca 2 Cu 3 O 6 “infinite-layer” blocks, while the latter has been proposed to have the structure of H- m 223:I or (H,C)- m 223 with an expanded blocking block. In the log( H irr ) vs. log(1− T / T c ) plot, the irreversibility-field lines for the two phases are found to be located at nearly the same position, comparable to the position reported previously for optimally-doped Hg-1223.
収録刊行物
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- Physica C: Superconductivity
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Physica C: Superconductivity 324 (2), 65-70, 1999-10
Elsevier BV
