Room temperature Mössbauer spectra of 57Fe-doped La2SrCu2O6, La2CaCu2O6 and La1.6Sr0.4CaCu2O6
Autor: | C. Meyer, Y. Gros, Pierre Strobel, F. Hartmann-Boutron |
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Rok vydání: | 1991 |
Předmět: |
Materials science
Energy Engineering and Power Technology chemistry.chemical_element Condensed Matter Physics Oxygen Copper Electronic Optical and Magnetic Materials Paramagnetism Crystallography Nuclear magnetic resonance chemistry Impurity Vacancy defect X-ray crystallography Quadrupole Electrical and Electronic Engineering Hyperfine structure |
Zdroj: | Physica C: Superconductivity. 181:1-10 |
ISSN: | 0921-4534 |
DOI: | 10.1016/0921-4534(91)90327-u |
Popis: | In order to elucidate the properties of iron in the pyramidal Cu(2) sites of YBa2Cu3O7-y, 1% 57Fe was substituted to copper in the simple bilayer compounds La2SrCu2O6 and La1.6Sr0.4CaCu2O6 (in their insulating forms). It appears that iron enters these systems as high-spin Fe3+. The room temperature Mossbauer spectra consist of paramagnetic quadrupole doublets, and a magnetic hyperfine structure appears below about 20 K. At RT , two quadrupolar doublets with ΔΔΔ ∼ 1 mm/s and ΔΔ ∼ 0.3 mm/s are observed in variable proportions in all three compounds. They have been interpreted by structural considerations involving, first a small displacement of the iron with respect to the copper position inside the oxygen pyramid, and second the possibility of additional oxygen insertion into 2b vacancy site, leading in some cases to an octahedral oxygen neighbourhood. |
Databáze: | OpenAIRE |
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