title: Magnetism and disorder effects on muon spin rotation measurements of the magnetic penetration depth in iron-arsenic superconductors.
abstract: It is shown that attempts to accurately deduce the magnetic penetration depth λ of overdoped BaFe(1.82)Co(0.18)As₂ single crystals by transverse-field muon spin rotation (TF μSR) are thwarted by field-induced magnetic order and strong vortex-lattice disorder. We explain how substantial deviations from the magnetic field distribution of a nearly perfect vortex lattice by one or both of these factors is also significant for other iron-arsenic superconductors, and this introduces considerable uncertainty in the values of λ obtained by TF μSR.
authors.affiliation: Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: J E
authors.initials: JE
authors.lastname: Sonier
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: C V
authors.initials: CV
authors.lastname: Kaiser
authors.forename: C
authors.initials: C
authors.lastname: Cochrane
authors.forename: V
authors.initials: V
authors.lastname: Pacradouni
authors.forename: S A
authors.initials: SA
authors.lastname: Sabok-Sayr
authors.forename: M D
authors.initials: MD
authors.lastname: Lumsden
authors.forename: B C
authors.initials: BC
authors.lastname: Sales
authors.forename: M A
authors.initials: MA
authors.lastname: McGuire
authors.forename: A S
authors.initials: AS
authors.lastname: Sefat
authors.forename: D
authors.initials: D
authors.lastname: Mandrus