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arXiv 1102.0357cond-mat.supr-concond-mat.mtrl-sci
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BaFe2As2局域原子结构中的压力和化学取代效应

Pressure and chemical substitution effects in the local atomic structure of BaFe2As2

E. Granado, L. Mendonca-Ferreira, F. Garcia, G. de M. Azevedo, G. Fabbris, E. M. Bittar, C. Adriano, T. M. Garitezi, P. F. S. Rosa, L. F. Bufaical, M. A. Avila,… 展开作者

E. Granado, L. Mendonca-Ferreira, F. Garcia, G. de M. Azevedo, G. Fabbris, E. M. Bittar, C. Adriano, T. M. Garitezi, P. F. S. Rosa, L. F. Bufaical, M. A. Avila, H. Terashita, P. G. Pagliuso

摘要:

用扩展X射线吸收精细结构(EXAFS)方法研究了BaFe_2As_2、Ba(Fe{0. 937}Co{0. 063})_2As_2和Ba{0. 85}K{0. 15} Fe_2As_2超导体在As_K吸收边的局域原子结构中K、Co替代和准流体静压(P<9 GPa)的影响. As-Fe键长被发现被Co和K取代略微减小(<~ 0.01埃),而相应的德拜沃勒因子没有任何可观察到的增加。此外,该键被证明是可压缩的(k = 3.3(3)x10^{-3} GPa^{-1})。在压力和化学取代作用下观察到的As-Fe键的收缩可能与局部Fe磁矩的减小有关,并且应该是Fe基超导体相图中的一个重要的调谐参数。

英文摘要:

The effects of K and Co substitutions and quasi-hydrostatic applied pressure (P<9 GPa) in the local atomic structure of BaFe2As2, Ba(Fe{0.937}Co{0.063})2As2 and Ba{0.85}K{0.15}Fe2As2 superconductors were investigated by extended x-ray absorption fine structure (EXAFS) measurements in the As K absorption edge. The As-Fe bond length is found to be slightly reduced (<~ 0.01 Angstroms) by both Co and K substitutions, without any observable increment in the corresponding Debye Waller factor. Also, this bond is shown to be compressible (k = 3.3(3)x10^{-3} GPa^{-1}). The observed contractions of As-Fe bond under pressure and chemical substitutions are likely related with a reduction of the local Fe magnetic moments, and should be an important tuning parameter in the phase diagrams of the Fe-based superconductors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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