Strong coupling between Eu2+spins and Fe2As2layers in EuFe1.9Co0.1As2observed with NMR
| Autor: | Sergiy Katrych, S. Strässle, J. Karpinski, Alexander Shengelaya, Zurab Guguchia, F. Murányi, Alexander Maisuradze, Zbigniew Bukowski, Stephen Weyeneth, J. Roos, Hugo Keller |
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| Rok vydání: | 2011 |
| Předmět: |
Physics
Condensed matter physics Spins Transition temperature 02 engineering and technology Electron 021001 nanoscience & nanotechnology Condensed Matter Physics Coupling (probability) 01 natural sciences Magnetic susceptibility Electronic Optical and Magnetic Materials NMR spectra database Magnetization 0103 physical sciences 010306 general physics 0210 nano-technology Hyperfine structure |
| Zdroj: | Physical Review B. 83 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.83.144516 |
| Popis: | A combination of x-ray diffraction, magnetization, and $^{75}\mathrm{As}$ nuclear magnetic resonance (NMR) experiments were performed on single-crystal EuFe${}_{1.9}$Co${}_{0.1}$As${}_{2}$. The strength of the hyperfine interaction between the $^{75}\mathrm{As}$ nuclei and the Eu${}^{2+}$ 4$f$ states suggests a strong coupling between the Eu${}^{2+}$ moments and the Fe${}_{1.9}$Co${}_{0.1}$As${}_{2}$ layers. Such a strong interlayer coupling may be due to an indirect exchange interaction between the localized Eu${}^{2+}$ 4$f$ moments, mediated by the Fe 3$d$ conduction electrons. Magnetic susceptibility as well as $^{75}\mathrm{As}$-NMR measurements reveal a decrease of the SDW transition temperature to ${T}_{\mathrm{SDW}}$ $=$ 120 K as a result of Co doping. A change of the slope in the temperature dependence of the NMR frequency of the $^{75}\mathrm{As}$ lower-satellite line was observed at 225 K. At the same temperature also a change of the satellite line shape was found. These changes of the NMR spectra may be caused by the formation of a nematic phase below 225 K in EuFe${}_{1.9}$Co${}_{0.1}$As${}_{2}$. |
| Databáze: | OpenAIRE |
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