title: Interfacial magnetic coupling between Fe nanoparticles in Fe–Ag granular alloys.
abstract: The role of the interface in mediating interparticle magnetic interactions has been analysed in Fe50Ag50 and Fe55Ag45 granular thin films deposited by the pulsed laser deposition technique (PLD). These samples are composed of crystalline bcc Fe (2–4 nm) nanoparticles and fcc Ag (10–12 nm) nanoparticles, separated by an amorphous Fe50Ag50 interface, occupying around 20% of the sample volume, as determined by x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and high resolution transmission electron microscopy (HRTEM). Interfacial magnetic coupling between Fe nanoparticles is studied by dc magnetization and x-ray magnetic circular dichroism (XMCD) measurements at the Fe K and Ag L2,3 edges. This paper reveals that these thin films present two magnetic transitions, at low and high temperatures, which are strongly related to the magnetic state of the amorphous interface, which acts as a barrier for interparticle magnetic coupling.
authors.affiliation: Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), Campus de Leioa, 48940 Leioa, Spain
authors.forename: J
authors.initials: J
authors.lastname: Alonso
authors.forename: M L
authors.initials: ML
authors.lastname: Fdez-Gubieda
authors.forename: G
authors.initials: G
authors.lastname: Sarmiento
authors.forename: J
authors.initials: J
authors.lastname: Chaboy
authors.forename: R
authors.initials: R
authors.lastname: Boada
authors.forename: A
authors.initials: A
authors.lastname: García Prieto
authors.forename: D
authors.initials: D
authors.lastname: Haskel
authors.forename: M A
authors.initials: MA
authors.lastname: Laguna-Marco
authors.forename: J C
authors.initials: JC
authors.lastname: Lang
authors.forename: C
authors.initials: C
authors.lastname: Meneghini
authors.forename: L
authors.initials: L
authors.lastname: Fernández Barquín
authors.forename: T
authors.initials: T
authors.lastname: Neisius
authors.forename: I
authors.initials: I
authors.lastname: Orue