title: Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition.
abstract: Segmented magnetic nanowires are a promising route for the development of three dimensional data storage techniques. Such devices require a control of the coercive field and the coupling mechanisms between individual magnetic elements. In our study, we investigate electrodeposited nanomagnets within host templates using vibrating sample magnetometry and observe a strong dependence between nanowire length and coercive field (25 nm-5 μm) and diameter (25-45 nm). A transition from a magnetization reversal through coherent rotation to domain wall propagation is observed at an aspect ratio of approximately 2. Our results are further reinforced via micromagnetic simulations and angle dependent hysteresis loops. The found behavior is exploited to create nanowires consisting of a fixed and a free segment in a spin-valve like structure. The wires are released from the membrane and electrically contacted, displaying a giant magnetoresistance effect that is attributed to individual switching of the coupled nanomagnets. We develop a simple analytical model to describe the observed switching phenomena and to predict stable and unstable regimes in coupled nanomagnets of certain geometries.
authors.affiliation: Institute of Nanostructure and Solid-State Physics, Universität Hamburg, D-20355 Hamburg, Germany.
authors.forename: Philip
authors.initials: P
authors.lastname: Sergelius
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Olivier
authors.initials: O
authors.lastname: Fruchart
authors.forename: Mohamed Shaker
authors.initials: MS
authors.lastname: Salem
authors.forename: Sebastian
authors.initials: S
authors.lastname: Allende
authors.forename: Roberto Alejandro
authors.initials: RA
authors.lastname: Escobar
authors.forename: Johannes
authors.initials: J
authors.lastname: Gooth
authors.forename: Robert
authors.initials: R
authors.lastname: Zierold
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Toussaint
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schneider
authors.forename: Darius
authors.initials: D
authors.lastname: Pohl
authors.forename: Bernd
authors.initials: B
authors.lastname: Rellinghaus
authors.forename: Sylvain
authors.initials: S
authors.lastname: Martin
authors.forename: Javier
authors.initials: J
authors.lastname: Garcia
authors.forename: Heiko
authors.initials: H
authors.lastname: Reith
authors.forename: Anne
authors.initials: A
authors.lastname: Spende
authors.forename: Maria-Eugenia
authors.initials: ME
authors.lastname: Toimil-Molares
authors.forename: Dora
authors.initials: D
authors.lastname: Altbir
authors.forename: Russel
authors.initials: R
authors.lastname: Cowburn
authors.forename: Detlef
authors.initials: D
authors.lastname: Görlitz
authors.forename: Kornelius
authors.initials: K
authors.lastname: Nielsch