Phys. Rev. B 80, 052503 (2009) [4 pages]Magnetic-superconducting phase boundary of SmFeAsO1−xFx studied via muon spin rotation: Unified behavior in a pnictide familyAbstract
Received 15 July 2009; published 13 August 2009 We present Muon spectroscopy investigations on SmFeAsO1-xFx 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 LaFeAsO1-xFx, 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. © 2009 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevB.80.052503
DOI:
10.1103/PhysRevB.80.052503
PACS:
74.25.Ha, 74.62.Dh, 74.70.−b, 76.75.+i
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