Pressure and chemical substitution effects in the local atomic structure of BaFe2As2
| Autor: | Granado, E., Mendonca-Ferreira, L., Garcia, F., Azevedo, G. de M., Fabbris, G., Bittar, E. M., Adriano, C., Garitezi, T. M., Rosa, P. F. S., Bufaical, L. F., Avila, M. A., Terashita, H., Pagliuso, P. G. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 83, 184508 (2011) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.83.184508 |
| Popis: | 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. Comment: 7 pages, 6 figures |
| Databáze: | arXiv |
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