title: Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study.
abstract: Near the point of equiatomic composition, both FeRh and FeCo bulk alloys exhibit a CsCl-type (B2) chemically ordered phase that is related to specific magnetic properties, namely a metamagnetic anti-ferromagnetic/ferromagnetic transition near room temperature for FeRh and a huge magnetic moment for the FeCo soft alloy. In this paper, we present the magnetic and structural properties of nanoparticles of less than 5 nm diameter embedded in an inert carbon matrix prepared by mass-selected low-energy cluster-beam deposition technique. We obtained a CsCl-type (B2) chemically ordered phase for annealed nanoalloys. Using different experimental measurements, we show how decreasing the size affects the magnetic properties. FeRh nanoparticles keep the ferromagnetic order at low temperature due to surface relaxation affecting the cell parameter. In the case of FeCo clusters, the environment drastically affects the intrinsic properties of this system by reducing the magnetization in comparison to the bulk.
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Dupuis
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Robert
authors.affiliation: Institut Jean Lamour, UMR7198, Université H. Poincarré-CNRS, F-5406 Vandoeuvre les Nancy, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Hillion
authors.affiliation: Interfaces, Confinement, Matériaux et Nanostructures, UMR7374 Université d'Orléans-CNRS, F-45071 Orléans cedex, France.
authors.forename: Ghassan
authors.initials: G
authors.lastname: Khadra
authors.affiliation: Université Grenoble Alpes, Inst NEEL, F-38000 Grenoble, France; CNRS, Inst NEEL, F-38000 Grenoble, France.
authors.forename: Nils
authors.initials: N
authors.lastname: Blanc
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Le Roy
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Tournus
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Clement
authors.initials: C
authors.lastname: Albin
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Boisron
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon F-69622 Villeurbanne cedex, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Tamion
keywords: bimetallic nanoparticles; magnetic moment and anisotropy; metamagnetic transition