Controlled domain wall pinning in ferromagnetic nanowire by nanoparticles stray fields

TL;DR

This study demonstrates controlled domain wall pinning in ferromagnetic nanowires using stray fields from adjacent nanoparticles, with experimental and simulation results showing tunable pinning strength for potential logic applications.

Contribution

It introduces a method to control domain wall pinning via nanoparticle stray fields, combining experimental magnetic force microscopy and micromagnetic simulations.

Findings

Pinning strength depends on nanoparticle magnetization orientation.

Pinning strength can reach up to 20 mT.

Magnetostatic interactions influence domain wall behavior.

Abstract

We report the results of experimental investigations of controlled domain wall (DW) pinning in a ferromagnetic nanowire (NW) by stray fields of two uniformly magnetized bistable ferromagnetic nanoparticles (NPs) placed on either side of the NW and elongated parallel to the NW axis. We show by magnetic force microscopy measurements that DW pinning strength essentially depends on the orientation of the NP magnetic moments relative to the NW magnetization and can reach 20 mT. We also performed micromagnetic simulations confirming the influence of the magnetostatic interaction of the DW with the NP stray fields on the pinning strength. The possible realization of logic cell with switchable logic function is discussed.