We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Gd electron spin resonance spectroscopy on LaOFFeAs superconductors.
- Authors
Alfonsov, A.; Murányi, F.; Leps, N.; Klingeler, R.; Kondrat, A.; Hess, C.; Wurmehl, S.; Köfiler, A.; Behr, G.; Kataev, V.; Büchner, B.
- Abstract
We report an electron spin resonance (ESR) spectroscopy study on polycrystalline samples of the LaOFFeAs ( x = 0 and 0.1) compound with small levels of Gd doping (2% and 5%). The Gd ESR signal is found to be sensitive to the magnetic phase transition from the paramagnetic to the spin density wave (SDW) state occurring in the parent LaOFFeAs compounds at T ∼ 130 K. Interestingly, the analysis of the low-temperature ESR spectra of the c-axis oriented GdLaOFeAs samples gives evidence for the magnetically nonequivalent Gd sites and also for sites having a different local charge environment. The analysis of the temperature dependence of the ESR linewidths gives evidence for a coupling of the localized 4 f electrons of Gd to the conduction electrons in the FeAs layers. The ESR data reveal that the fluorine substitution, which provides electron doping, suppresses the SDW order and enhances the density of states in the electronic bands stemming from the xz and yz orbital states of Fe to which the 4 f electrons are most strongly coupled.
- Subjects
ELECTRON paramagnetic resonance spectroscopy; LANTHANUM compounds; SUPERCONDUCTORS; POLYCRYSTALS; CHEMICAL sample preparation; PHASE transitions; DENSITY wave theory
- Publication
Journal of Experimental & Theoretical Physics, 2012, Vol 114, Issue 4, p662
- ISSN
1063-7761
- Publication type
Article
- DOI
10.1134/S1063776112030120