Phase identification of the new 126 K Ba-Ca-Cu-O superconductor

Y. Y. Xue, Y. Y. Sun, I. Rusakova, D. K. Ross, Z. L. Du, N. L. Wu, Y. Cao, L. Gao, B. Hickey, C. W. Chu

研究成果: Article同行評審

22 引文 斯高帕斯(Scopus)

摘要

New superconducting oxides that have a composition of Ba2Ca2Cu3(CaxCuy)O 8+δ with 0.4 ≥ x ≥ 0.9 and 0.7 ≥ y ≥ 0, and show an optimum Tc ∼ 126 K were identified. Structural analysis, based on X-ray diffraction, indicated a common tetragonal unit cell among these oxides, which has lattice constants a = 3.85 Å and c = 28.2 Å with an I/4mmm symmetry. The cell consists of a rock-salt (BaO)2 block sandwiched between two perovskite Ca2Cu3O6 blocks with interstitial Ca+2x and Cu+2y located, e.g. at the 4d site between the two BaO planes. In other words, a so-called 0223 cell with interstitial CaxCuy. The oxides differ from one another by the amounts of the inserted cations, i.e. the values of x and y. The presence of these interstitial cations offers a new way to adjust the carrier concentration. These oxides are unstable against the incorporation of H2O and CO2 in open air. The decayed products (Ca,Cu,H,CO2)2Ba2Ca2Cu 3O8+δ have an expanded lattice constant c ∼ 33.8 Å and a lower Tc ∼ 90 K. A structure model for the decayed phases was also proposed.

原文English
頁(從 - 到)316-326
頁數11
期刊Physica C: Superconductivity and its applications
294
發行號3-4
DOIs
出版狀態Published - 1998 一月 1

All Science Journal Classification (ASJC) codes

  • 電子、光磁材料
  • 凝聚態物理學
  • 能源工程與電力技術
  • 電氣與電子工程

指紋

深入研究「Phase identification of the new 126 K Ba-Ca-Cu-O superconductor」主題。共同形成了獨特的指紋。

引用此