Synthesis and superconductivity of barium deficient type I silicon clathrate compounds, Ba8-xSi46

被引：41

作者：

Fukuoka, H ^{[1
]}

Kiyoto, J ^{[1
]}

Yamanaka, S ^{[1
]}

机构：

[1] Hiroshima Univ, Grad Sch Engn, Dept Appl Chem, Hiroshima 7398527, Japan

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 2004年 / 65卷 / 2-3期

关键词：

superconductors; superconductivity; defects; electrical properties;

D O I：

10.1016/j.jpcs.2003.10.025

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Barium deficient Type I silicon clathrate compounds, Ba8-xSi46, were prepared by high-pressure and high-temperature conditions. The single phases were obtained by the reactions under pressures higher than 3 GPa and temperatures higher than 800 K. They showed superconductivity with critical temperatures (T(c)s) ranging from 8.2 to 9.0 K. The composition of the compound having the highest T-c of 9.0 K was determined to be Ba7.76Si46 from the single crystal X-ray analysis. On annealing at 800 K in vacuum, a part of Ba atoms were deintercalated from the silicon cages of the clathrate structure. The T-c decreased with the increase of the Ba deficiency down to 5.0 K for Ba6.62Si46. The density of states of Ba6Si46 was calculated, and compared with those of the defect-free Ba8Si46. (C) 2003 Elsevier Ltd. All rights reserved.

引用

页码：333 / 336

页数：4

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