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arXiv · 1612.00314

Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition

Philip Sergelius·Ji Lee·Olivier Fruchart·Mohamed Salem·Sebastian Allende·Robert Escobar·Johannes Gooth·Robert Zierold·Jean-Christophe Toussaint·Sebastian Schneider·Darius Pohl·Bernd Rellinghaus·Sylvain Martin·Javier Garcia·Heiko Reith·Anne Spende·Maria Toimil-Molares·Dora Altbir·Russel Cowburn·Detlef Görlitz·Kornelius Nielsch
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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 to 5 $\mu$m) and diameter (25 nm to 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.

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Philip Sergelius, Ji Lee, Olivier Fruchart, Mohamed Salem, Sebastian Allende, Robert Escobar, Johannes Gooth, Robert Zierold, Jean-Christophe Toussaint, Sebastian Schneider, Darius Pohl, Bernd Rellinghaus, Sylvain Martin, Javier Garcia, Heiko Reith, Anne Spende, Maria Toimil-Molares, Dora Altbir, Russel Cowburn, Detlef Görlitz, Kornelius Nielsch. 2016-12-01. Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition. https://doi.org/10.1088/1361-6528%2Faa5118

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