Magnetization Reversal Across Multiple Serial Barriers in a Single Fe$_3$O$_4$ Nanoparticle

TL;DR

This study investigates the magnetization reversal process in a single Fe₃O₄ nanoparticle, revealing that multiple serial energy barriers influence the switching dynamics, which is crucial for magnetic storage technologies.

Contribution

It demonstrates that magnetization reversal involves multiple serial barriers, challenging the assumption of a single energy barrier in nanoscale magnetic particles.

Findings

Narrowing of waiting-time distributions observed

Magnetization reversal involves multiple barriers

Implications for magnetic storage design

Abstract

Depinning of nanoscale magnetic textures, such as domain walls, vortices and skyrmions, is of paramount importance for magnetic storage and information processing. We measure time-resolved magnetic switching statistics of an individual, non-single-domain Fe$_3$O$_4$ nanoparticle using a micrometer-scale superconducting quantum interference device. Surprisingly, a strong narrowing of the waiting-time distributions before reaching the final state is observed as compared to the exponential distribution expected for a single barrier. The magnetization reversal across the nanostructure is thus shown to result from multiple serial barriers in the minimum energy pathway.