Magnetization reversal behavior in complex shaped Co nanowires: a nanomagnet morphology optimization

TL;DR

This study investigates how the shape and size of complex Co nanowires influence their magnetic reversal behavior, revealing that diameter and head shape are crucial beyond a certain aspect ratio, with implications for magnetic device optimization.

Contribution

It provides a systematic micromagnetic analysis of morphological effects on Co nanowires, highlighting the importance of diameter and head shape in magnetization reversal beyond an aspect ratio of 10.

Findings

Aspect ratio > 10 reduces the importance of length in magnetic behavior.

Head shape influences demagnetizing field distribution and reversal nucleation.

Angular magnetization dependence aligns with prolate spheroid models.

Abstract

A systematic micromagnetic study of the morphological characteristic effects over the magnetic static properties of Co-based complex shaped nanowires is presented. The relevance of each characteristic size (i.e. length L, diameter d, and size of the nanowires head T) and their critical values are discussed in the coercive field optimization goal. Our results strongly confirms that once the aspect ratio (L/d) of the nanowire is bigger than around 10, the length is no more the pertinent parameter and instead the internal diameter and the shape of the nanowires play a key role. We attribute this behavior to the non uniform distribution of the demagnetizing field which is localized in the nanowires head and acts as a nucleation point for the incoherent magnetization reversal. Finally, angular dependence of the magnetization are simulated and compared to the case of a prolate spheroid for all considered morphologies.