Flexible ferromagnetic nanowires with ultralow magnetostriction

TL;DR

This paper reports the first realization of flexible ferromagnetic nanowires on substrates, demonstrating ultralow magnetostriction, high resilience, and potential for wearable spintronic sensors and flexible magneto-plasmonic devices.

Contribution

It introduces flexible ferromagnetic nanowires with significantly reduced magnetostrictive constants and enhanced mechanical resilience, advancing flexible spintronic and magneto-plasmonic technologies.

Findings

Two-order magnitude reduction in magnetostriction compared to bulk

Nanowires sustain bending radii ~5 mm with high endurance

Enhanced elastic limit compared to thin films

Abstract

Integration of magneto-electric and spintronic sensors presents a massive potential for advancing flexible and wearable technology. Magnetic nanowires are core components for building such devices, and therefore it important to realize flexible magnetic nanowires and uncover magneto-elastic properties, which can propel not only such flexible sensing applications, but can also make new pathways for exploration of flexible magneto-plasmonic devices, and discovering unseen observations at reduced dimensions. Here, we realize ferromagnetic nanowires on flexible substrates for the first time. Through extensive magneto-optical Kerr experiments, exploring the Villari effect in such nanowires, we reveal a two-order of magnitude reduced magnetostrictive constant in nanowires, compared to bulk values. In addition, the nanowires exhibit a remarkably resilient behavior sustaining bending radii ~ 5 mm, very high endurance, and enhanced elastic limit compared to thin films of similar thickness and composition. We confirm the observed performance by micro-magnetic simulations and attribute the observations to the size reduction and high nanostructure-interfacial effects. The flexible magnetic nanowires with ultralow magnetostriction open up new opportunities for stable surface mountable and wearable spintronic sensors, enable a credible way for engineering advanced nanospintronic devices and exploring new effects in hybrid heterostructures.