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arXiv · 0902.2156

Magnetic-superconducting phase boundary of SmFeAsO$_{1-x}$F$_{x}$ studied via muon spin rotation: Unified behavior in a pnictide family

S. Sanna·R. De Renzi·G. Lamura·C. Ferdeghini·A. Palenzona·M. Putti·M. Tropeano·T. Shiroka
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Abstract

We present uSR investigations on SmFeAsO_1-xF_x showing coexistence of magnetic order and superconductivity only in a very narrow F-doping range. The sharp crossover between the two types of order is similar to that observed in LaFeAsO_1-xF_x, suggesting a common behavior for the 1111 pnictides. The analysis of the muon asymmetry demonstrates that the coexistence must be nanoscopic, i.e. the two phases must be finely interspersed over a typical length-scale of few nm. In this regime both the magnetic and the superconducting transition temperatures collapse to very low values. Our data suggest a competition between the two order parameters

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S. Sanna, R. De Renzi, G. Lamura, C. Ferdeghini, A. Palenzona, M. Putti, M. Tropeano, T. Shiroka. 2009-07-27. Magnetic-superconducting phase boundary of SmFeAsO$_{1-x}$F$_{x}$ studied via muon spin rotation: Unified behavior in a pnictide family. https://doi.org/10.1103/physrevb.80.052503

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