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arXiv · 0805.0264

Commensurate Spin Density Wave in LaOFeAs: A Local Probe Study

H. -H. Klauss·H. Luetkens·R. Klingeler·C. Hess·F. J. Litterst·M. Kraken·M. M. Korshunov·I. Eremin·S. -L. Drechsler·R. Khasanov·A. Amato·J. Hamann-Borreo·N. Leps·A. Kondrat·G. Behr·J. Werner·B. Buechner
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Abstract

We present a detailed study on the magnetic order in the undoped mother compound LaOFeAs of the recently discovered Fe-based superconductor LaO$_{1-x}$F$_x$FeAs. In particular, we present local probe measurements of the magnetic properties of LaOFeAs by means of $^{57}$Fe Mössbauer spectroscopy and muon spin relaxation in zero external field along with magnetization and resistivity studies. These experiments prove a commensurate static magnetic order with a strongly reduced ordered moment of 0.25(5) $μ_B$ at the iron site below T_N = 138 K, well separated from a structural phase transition at T_N = 156 K. The temperature dependence of the sublattice magnetization is determined and compared to theory. Using a four-band spin density wave model both, the size of the order parameter and the quick saturation below T_N are reproduced.

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H. -H. Klauss, H. Luetkens, R. Klingeler, C. Hess, F. J. Litterst, M. Kraken, M. M. Korshunov, I. Eremin, S. -L. Drechsler, R. Khasanov, A. Amato, J. Hamann-Borreo, N. Leps, A. Kondrat, G. Behr, J. Werner, B. Buechner. 2008-08-28. Commensurate Spin Density Wave in LaOFeAs: A Local Probe Study. https://doi.org/10.1103/physrevlett.101.077005

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