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arXiv · 0904.3173

Electronic and Magnetic Phase Diagram of a Superconductor, SmFeAsO1-xFx

Yoichi Kamihara·Takatoshi Nomura·Masahiro Hirano·Jung Eun Kim·Kenichi Kato·Masaki Takata·Yasuhiro Kobayashi·Shinji Kitao·Satoshi Higashitaniguchi·Yoshitaka Yoda·Makoto Seto·Hideo Hosono
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Abstract

A crystallographic and magnetic phase diagram of SmFeAsO1-xFx is determined as a function of x in terms of temperature based on electrical transport and magnetization, synchrotron powder x-ray diffraction, 57Fe Mossbauer spectra (MS), and 149Sm nuclear resonant forward scattering (NRFS) measurements. MS revealed that the magnetic moments of Fe were aligned antiferromagnetically at ~144 K (TN(Fe)). The magnetic moment of Fe (MFe) is estimated to be 0.34 myuB/Fe at 4.2 K for undoped SmFeAsO; MFe is quenched in superconducting F-doped SmFeAsO. 149Sm NRFS spectra revealed that the magnetic moments of Sm start to order antiferromagnetically at 5.6 K (undoped) and 4.4 K (TN(Sm)) (x = 0.069). Results clearly indicate that the antiferromagnetic Sm sublattice coexists with the superconducting phase in SmFeAsO1-xFx below TN(Sm), while antiferromagnetic Fe sublattice does not coexist with the superconducting phase.

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Yoichi Kamihara, Takatoshi Nomura, Masahiro Hirano, Jung Eun Kim, Kenichi Kato, Masaki Takata, Yasuhiro Kobayashi, Shinji Kitao, Satoshi Higashitaniguchi, Yoshitaka Yoda, Makoto Seto, Hideo Hosono. 2010-01-31. Electronic and Magnetic Phase Diagram of a Superconductor, SmFeAsO1-xFx. https://doi.org/10.1088/1367-2630%2F12%2F3%2F033005

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