title: Muon spin rotation and relaxation in the superconducting ferromagnet UCoGe.
abstract: We report zero-field muon-spin rotation and relaxation measurements on the superconducting ferromagnet UCoGe. Weak itinerant ferromagnetic order is detected by a spontaneous muon-spin precession frequency below the Curie temperature TC=3 K. The micro+ precession frequency persists below the bulk superconducting transition temperature Tsc=0.5 K, where it measures a local magnetic field Bloc=0.015 T. The amplitude of the microSR signal provides unambiguous proof for ferromagnetism present in the whole sample volume. We conclude ferromagnetism coexists with superconductivity on the microscopic scale.
authors.affiliation: Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands. a.devisser@uva.nl
authors.forename: A
authors.initials: A
authors.lastname: de Visser
authors.forename: N T
authors.initials: NT
authors.lastname: Huy
authors.forename: A
authors.initials: A
authors.lastname: Gasparini
authors.forename: D E
authors.initials: DE
authors.lastname: de Nijs
authors.forename: D
authors.initials: D
authors.lastname: Andreica
authors.forename: C
authors.initials: C
authors.lastname: Baines
authors.forename: A
authors.initials: A
authors.lastname: Amato