Tunnel barrier enhanced voltage signals generated by magnetization precession of a single ferromagnetic layer

TL;DR

This paper demonstrates that a tunnel barrier significantly amplifies voltage signals generated by magnetization precession in a ferromagnetic layer, highlighting a potential method for improved magnetic sensing.

Contribution

The study introduces a tunnel junction structure that enhances voltage signals from magnetization precession, advancing detection sensitivity in spintronic devices.

Findings

Voltage signals are amplified about tenfold with a tunnel barrier.

Precessing ferromagnet generates measurable dc voltage under FMR conditions.

Discussion links the phenomenon to magnetic spin pumping and other mechanisms.

Abstract

We report the electrical detection of magnetization dynamics in an Al/AlOx/Ni80Fe20/Cu tunnel junction, where a Ni80Fe20 ferromagnetic layer is brought into precession under the ferromagnetic resonance (FMR) conditions. The dc voltage generated across the junction by the precessing ferromagnet is enhanced about an order of magnitude compared to the voltage signal observed when the contacts in this type of multilayered structure are ohmic. We discuss the relation of this phenomenon to magnetic spin pumping and speculate on other possible underlying mechanisms responsible for the enhanced electrical signal.