Synthesis, crystal structures and superconductivity of new copper oxyfluorides, Sr(2)RCu(2)O(5)F (R=Y,La,Nd,Sm,Gd,Dy,Er and Yb)

被引：15

作者：

Isobe, M

Li, JQ

Matsui, Y

Izumi, F

Kanke, Y

TakayamaMuromachi, E

机构：

[1] Natl. Inst. for Res. in Inorg. Mat., Tsukuba, Ibaraki 305

[2] Natl. Lab. for Superconductivity, Institute of Physics, Chinese Academy of Sciences, Beijing

来源：

PHYSICA C | 1996年 / 269卷 / 1-2期

关键词：

high-T-c superconductor; high-pressure synthesis; oxyfluoride compounds; Sr(2)RCu(2)O(5)F; Rietveld analysis;

D O I：

10.1016/0921-4534(96)00430-3

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

A new series of oxyfluoride compounds, Sr(2)RCu(2)O(5)F (R = Y,La,Nd,Sm,Gd,Dy,Er and Yb), was successfully synthesized under high pressure of 6 GPa. Electron microscopic observation and X-ray Rietveld analysis indicated that they are essentially isostructural to La2SrCu2O (tetragonal, 14/mmm) with a half of apical oxygen sites of CuO5 pyramids replaced by F atoms. Superconductivity occurred in the Nd analogue after Ca substitution for x greater than or equal to 0.5 in Sr2Nd1-xCaxCu2O5F. A single-phase sample of the Nd analogue was obtained at x = 0.8 having the highest T-c of 85 K with a Meissner fraction of 6.8% and a shielding fraction of 7.4% at 5 K. These small fractions suggest a small grain size, weak intergrain coupling and/or weak pinning force.

引用

页码：5 / 14

页数：10

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